File:  [LON-CAPA] / loncom / lond
Revision 1.110: download - view: text, annotated - select for diffs
Sun Mar 2 03:58:55 2003 UTC (21 years, 1 month ago) by www
Branches: MAIN
CVS tags: HEAD
Fixes possible security problem.

#!/usr/bin/perl
# The LearningOnline Network
# lond "LON Daemon" Server (port "LOND" 5663)
#
# $Id: lond,v 1.110 2003/03/02 03:58:55 www Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
# 5/26/99,6/4,6/10,6/11,6/14,6/15,6/26,6/28,6/30,
# 7/8,7/9,7/10,7/12,7/17,7/19,9/21,
# 10/7,10/8,10/9,10/11,10/13,10/15,11/4,11/16,
# 12/7,12/15,01/06,01/11,01/12,01/14,2/8,
# 03/07,05/31 Gerd Kortemeyer
# 06/29,06/30,07/14,07/15,07/17,07/20,07/25,09/18 Gerd Kortemeyer
# 12/05,12/13,12/29 Gerd Kortemeyer
# YEAR=2001
# 02/12 Gerd Kortemeyer
# 03/24 Gerd Kortemeyer
# 05/11,05/28,08/30 Gerd Kortemeyer
# 11/26,11/27 Gerd Kortemeyer
# 12/22 Gerd Kortemeyer
# YEAR=2002
# 01/20/02,02/05 Gerd Kortemeyer
# 02/05 Guy Albertelli
# 02/12 Gerd Kortemeyer
# 02/19 Matthew Hall
# 02/25 Gerd Kortemeyer
# 01/xx/2003 Ron Fox.. Remove preforking.  This makes the general daemon
#      logic simpler (and there were problems maintaining the preforked
#      population).  Since the time averaged connection rate is close to zero
#      because lonc's purpose is to maintain near continuous connnections,
#      preforking is not really needed.
###


use lib '/home/httpd/lib/perl/';
use LONCAPA::Configuration;

use IO::Socket;
use IO::File;
use Apache::File;
use Symbol;
use POSIX;
use Crypt::IDEA;
use LWP::UserAgent();
use GDBM_File;
use Authen::Krb4;
use Authen::Krb5;
use lib '/home/httpd/lib/perl/';
use localauth;

my $DEBUG = 0;		       # Non zero to enable debug log entries.

my $status='';
my $lastlog='';

#
#  The array below are password error strings."
#
my $lastpwderror    = 13;		# Largest error number from lcpasswd.
my @passwderrors = ("ok",
		   "lcpasswd must be run as user 'www'",
		   "lcpasswd got incorrect number of arguments",
		   "lcpasswd did not get the right nubmer of input text lines",
		   "lcpasswd too many simultaneous pwd changes in progress",
		   "lcpasswd User does not exist.",
		   "lcpasswd Incorrect current passwd",
		   "lcpasswd Unable to su to root.",
		   "lcpasswd Cannot set new passwd.",
		   "lcpasswd Username has invalid characters",
		   "lcpasswd Invalid characters in password",
		    "11", "12",
		    "lcpasswd Password mismatch");


#  The array below are lcuseradd error strings.:

my $lastadderror = 13;
my @adderrors    = ("ok",
		    "User ID mismatch, lcuseradd must run as user www",
		    "lcuseradd Incorrect number of command line parameters must be 3",
		    "lcuseradd Incorrect number of stdinput lines, must be 3",
		    "lcuseradd Too many other simultaneous pwd changes in progress",
		    "lcuseradd User does not exist",
		    "lcuseradd Unabel to mak ewww member of users's group",
		    "lcuseradd Unable to su to root",
		    "lcuseradd Unable to set password",
		    "lcuseradd Usrname has invbalid charcters",
		    "lcuseradd Password has an invalid character",
		    "lcuseradd User already exists",
		    "lcuseradd Could not add user.",
		    "lcuseradd Password mismatch");


#
#  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
sub catchexception {
    my ($error)=@_;
    $SIG{'QUIT'}='DEFAULT';
    $SIG{__DIE__}='DEFAULT';
    &logthis("<font color=red>CRITICAL: "
     ."ABNORMAL EXIT. Child $$ for server $wasserver died through "
     ."a crash with this error msg->[$error]</font>");
    &logthis('Famous last words: '.$status.' - '.$lastlog);
    if ($client) { print $client "error: $error\n"; }
    $server->close();
    die($error);
}

sub timeout {
    &logthis("<font color=ref>CRITICAL: TIME OUT ".$$."</font>");
    &catchexception('Timeout');
}
# -------------------------------- Set signal handlers to record abnormal exits

$SIG{'QUIT'}=\&catchexception;
$SIG{__DIE__}=\&catchexception;

# ---------------------------------- Read loncapa_apache.conf and loncapa.conf
&status("Read loncapa.conf and loncapa_apache.conf");
my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
my %perlvar=%{$perlvarref};
undef $perlvarref;

# ----------------------------- Make sure this process is running from user=www
my $wwwid=getpwnam('www');
if ($wwwid!=$<) {
   $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
   $subj="LON: $perlvar{'lonHostID'} User ID mismatch";
   system("echo 'User ID mismatch.  lond must be run as user www.' |\
 mailto $emailto -s '$subj' > /dev/null");
   exit 1;
}

# --------------------------------------------- Check if other instance running

my $pidfile="$perlvar{'lonDaemons'}/logs/lond.pid";

if (-e $pidfile) {
   my $lfh=IO::File->new("$pidfile");
   my $pide=<$lfh>;
   chomp($pide);
   if (kill 0 => $pide) { die "already running"; }
}

$PREFORK=4; # number of children to maintain, at least four spare

# ------------------------------------------------------------- Read hosts file

open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";

while ($configline=<CONFIG>) {
    my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
    chomp($ip); $ip=~s/\D+$//;
    $hostid{$ip}=$id;
    if ($id eq $perlvar{'lonHostID'}) { $thisserver=$name; }
    $PREFORK++;
}
close(CONFIG);

# establish SERVER socket, bind and listen.
$server = IO::Socket::INET->new(LocalPort => $perlvar{'londPort'},
                                Type      => SOCK_STREAM,
                                Proto     => 'tcp',
                                Reuse     => 1,
                                Listen    => 10 )
  or die "making socket: $@\n";

# --------------------------------------------------------- Do global variables

# global variables

$MAX_CLIENTS_PER_CHILD  = 50;        # number of clients each child should 
                                    # process
%children               = ();       # keys are current child process IDs
$children               = 0;        # current number of children

sub REAPER {                        # takes care of dead children
    $SIG{CHLD} = \&REAPER;
    my $pid = wait;
    if (defined($children{$pid})) {
	&logthis("Child $pid died");
	$children --;
	delete $children{$pid};
    } else {
	&logthis("Unknown Child $pid died");
    }
}

sub HUNTSMAN {                      # signal handler for SIGINT
    local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
    kill 'INT' => keys %children;
    &logthis("Free socket: ".shutdown($server,2)); # free up socket
    my $execdir=$perlvar{'lonDaemons'};
    unlink("$execdir/logs/lond.pid");
    &logthis("<font color=red>CRITICAL: Shutting down</font>");
    exit;                           # clean up with dignity
}

sub HUPSMAN {                      # signal handler for SIGHUP
    local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children
    kill 'INT' => keys %children;
    &logthis("Free socket: ".shutdown($server,2)); # free up socket
    &logthis("<font color=red>CRITICAL: Restarting</font>");
    unlink("$execdir/logs/lond.pid");
    my $execdir=$perlvar{'lonDaemons'};
    exec("$execdir/lond");         # here we go again
}

sub checkchildren {
    &initnewstatus();
    &logstatus();
    &logthis('Going to check on the children');
    $docdir=$perlvar{'lonDocRoot'};
    foreach (sort keys %children) {
	sleep 1;
        unless (kill 'USR1' => $_) {
	    &logthis ('Child '.$_.' is dead');
            &logstatus($$.' is dead');
        } 
    }
    sleep 5;
    foreach (sort keys %children) {
        unless (-e "$docdir/lon-status/londchld/$_.txt") {
	    &logthis('Child '.$_.' did not respond');
	    kill 9 => $_;
	    $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
	    $subj="LON: $perlvar{'lonHostID'} killed lond process $_";
	    my $result=`echo 'Killed lond process $_.' | mailto $emailto -s '$subj' > /dev/null`;
	    $execdir=$perlvar{'lonDaemons'};
	    $result=`/bin/cp $execdir/logs/lond.log $execdir/logs/lond.log.$_`
        }
    }
}

# --------------------------------------------------------------------- Logging

sub logthis {
    my $message=shift;
    my $execdir=$perlvar{'lonDaemons'};
    my $fh=IO::File->new(">>$execdir/logs/lond.log");
    my $now=time;
    my $local=localtime($now);
    $lastlog=$local.': '.$message;
    print $fh "$local ($$): $message\n";
}

# ------------------------- Conditional log if $DEBUG true.
sub Debug {
    my $message = shift;
    if($DEBUG) {
	&logthis($message);
    }
}
# ------------------------------------------------------------------ Log status

sub logstatus {
    my $docdir=$perlvar{'lonDocRoot'};
    {
    my $fh=IO::File->new(">>$docdir/lon-status/londstatus.txt");
    print $fh $$."\t".$status."\t".$lastlog."\n";
    $fh->close();
    }
    {
	my $fh=IO::File->new(">$docdir/lon-status/londchld/$$.txt");
        print $fh $status."\n".$lastlog."\n".time;
        $fh->close();
    }
}

sub initnewstatus {
    my $docdir=$perlvar{'lonDocRoot'};
    my $fh=IO::File->new(">$docdir/lon-status/londstatus.txt");
    my $now=time;
    my $local=localtime($now);
    print $fh "LOND status $local - parent $$\n\n";
    opendir(DIR,"$docdir/lon-status/londchld");
    while ($filename=readdir(DIR)) {
        unlink("$docdir/lon-status/londchld/$filename");
    }
    closedir(DIR);
}

# -------------------------------------------------------------- Status setting

sub status {
    my $what=shift;
    my $now=time;
    my $local=localtime($now);
    $status=$local.': '.$what;
    $0='lond: '.$what.' '.$local;
}

# -------------------------------------------------------- Escape Special Chars

sub escape {
    my $str=shift;
    $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
    return $str;
}

# ----------------------------------------------------- Un-Escape Special Chars

sub unescape {
    my $str=shift;
    $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
    return $str;
}

# ----------------------------------------------------------- Send USR1 to lonc

sub reconlonc {
    my $peerfile=shift;
    &logthis("Trying to reconnect for $peerfile");
    my $loncfile="$perlvar{'lonDaemons'}/logs/lonc.pid";
    if (my $fh=IO::File->new("$loncfile")) {
	my $loncpid=<$fh>;
        chomp($loncpid);
        if (kill 0 => $loncpid) {
	    &logthis("lonc at pid $loncpid responding, sending USR1");
            kill USR1 => $loncpid;
            sleep 5;
            if (-e "$peerfile") { return; }
            &logthis("$peerfile still not there, give it another try");
            sleep 10;
            if (-e "$peerfile") { return; }
            &logthis(
 "<font color=blue>WARNING: $peerfile still not there, giving up</font>");
        } else {
	    &logthis(
              "<font color=red>CRITICAL: "
             ."lonc at pid $loncpid not responding, giving up</font>");
        }
    } else {
      &logthis('<font color=red>CRITICAL: lonc not running, giving up</font>');
    }
}

# -------------------------------------------------- Non-critical communication

sub subreply {
    my ($cmd,$server)=@_;
    my $peerfile="$perlvar{'lonSockDir'}/$server";
    my $sclient=IO::Socket::UNIX->new(Peer    =>"$peerfile",
                                      Type    => SOCK_STREAM,
                                      Timeout => 10)
       or return "con_lost";
    print $sclient "$cmd\n";
    my $answer=<$sclient>;
    chomp($answer);
    if (!$answer) { $answer="con_lost"; }
    return $answer;
}

sub reply {
  my ($cmd,$server)=@_;
  my $answer;
  if ($server ne $perlvar{'lonHostID'}) { 
    $answer=subreply($cmd,$server);
    if ($answer eq 'con_lost') {
	$answer=subreply("ping",$server);
        if ($answer ne $server) {
	    &logthis("sub reply: answer != server");
           &reconlonc("$perlvar{'lonSockDir'}/$server");
        }
        $answer=subreply($cmd,$server);
    }
  } else {
    $answer='self_reply';
  } 
  return $answer;
}

# -------------------------------------------------------------- Talk to lonsql

sub sqlreply {
    my ($cmd)=@_;
    my $answer=subsqlreply($cmd);
    if ($answer eq 'con_lost') { $answer=subsqlreply($cmd); }
    return $answer;
}

sub subsqlreply {
    my ($cmd)=@_;
    my $unixsock="mysqlsock";
    my $peerfile="$perlvar{'lonSockDir'}/$unixsock";
    my $sclient=IO::Socket::UNIX->new(Peer    =>"$peerfile",
                                      Type    => SOCK_STREAM,
                                      Timeout => 10)
       or return "con_lost";
    print $sclient "$cmd\n";
    my $answer=<$sclient>;
    chomp($answer);
    if (!$answer) { $answer="con_lost"; }
    return $answer;
}

# -------------------------------------------- Return path to profile directory

sub propath {
    my ($udom,$uname)=@_;
    $udom=~s/\W//g;
    $uname=~s/\W//g;
    my $subdir=$uname.'__';
    $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
    my $proname="$perlvar{'lonUsersDir'}/$udom/$subdir/$uname";
    return $proname;
} 

# --------------------------------------- Is this the home server of an author?

sub ishome {
    my $author=shift;
    $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
    my ($udom,$uname)=split(/\//,$author);
    my $proname=propath($udom,$uname);
    if (-e $proname) {
	return 'owner';
    } else {
        return 'not_owner';
    }
}

# ======================================================= Continue main program
# ---------------------------------------------------- Fork once and dissociate

$fpid=fork;
exit if $fpid;
die "Couldn't fork: $!" unless defined ($fpid);

POSIX::setsid() or die "Can't start new session: $!";

# ------------------------------------------------------- Write our PID on disk

$execdir=$perlvar{'lonDaemons'};
open (PIDSAVE,">$execdir/logs/lond.pid");
print PIDSAVE "$$\n";
close(PIDSAVE);
&logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");
&status('Starting');



# ----------------------------------------------------- Install signal handlers


$SIG{CHLD} = \&REAPER;
$SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
$SIG{HUP}  = \&HUPSMAN;
$SIG{USR1} = \&checkchildren;



# --------------------------------------------------------------
#   Accept connections.  When a connection comes in, it is validated
#   and if good, a child process is created to process transactions
#   along the connection.

while (1) {
    $client = $server->accept() or next;
    make_new_child($client);
}

sub make_new_child {
    my $client;
    my $pid;
    my $cipher;
    my $sigset;

    $client = shift;
    &logthis("Attempting to start child");    
    # block signal for fork
    $sigset = POSIX::SigSet->new(SIGINT);
    sigprocmask(SIG_BLOCK, $sigset)
        or die "Can't block SIGINT for fork: $!\n";
    
    die "fork: $!" unless defined ($pid = fork);
    
    if ($pid) {
        # Parent records the child's birth and returns.
        sigprocmask(SIG_UNBLOCK, $sigset)
            or die "Can't unblock SIGINT for fork: $!\n";
        $children{$pid} = 1;
        $children++;
        &status('Started child '.$pid);
        return;
    } else {
        # Child can *not* return from this subroutine.
        $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
        $SIG{USR1}= \&logstatus;
        $SIG{ALRM}= \&timeout;
        $lastlog='Forked ';
        $status='Forked';

        # unblock signals
        sigprocmask(SIG_UNBLOCK, $sigset)
            or die "Can't unblock SIGINT for fork: $!\n";

        $tmpsnum=0;
#---------------------------------------------------- kerberos 5 initialization
        &Authen::Krb5::init_context();
        &Authen::Krb5::init_ets();

            &status('Accepted connection');
# =============================================================================
            # do something with the connection
# -----------------------------------------------------------------------------
	    $client->sockopt(SO_KEEPALIVE, 1);# Enable monitoring of
	                                      # connection liveness.
            # see if we know client and check for spoof IP by challenge
		my $caller = getpeername($client);
            my ($port,$iaddr)=unpack_sockaddr_in($caller);
            my $clientip=inet_ntoa($iaddr);
            my $clientrec=($hostid{$clientip} ne undef);
            &logthis(
"<font color=yellow>INFO: Connection $i, $clientip ($hostid{$clientip})</font>"
            );
            &status("Connecting $clientip ($hostid{$clientip})"); 
            my $clientok;
            if ($clientrec) {
	      &status("Waiting for init from $clientip ($hostid{$clientip})");
	      my $remotereq=<$client>;
              $remotereq=~s/\W//g;
              if ($remotereq eq 'init') {
		  my $challenge="$$".time;
                  print $client "$challenge\n";
                  &status(
           "Waiting for challenge reply from $clientip ($hostid{$clientip})"); 
                  $remotereq=<$client>;
                  $remotereq=~s/\W//g;
                  if ($challenge eq $remotereq) {
		      $clientok=1;
                      print $client "ok\n";
                  } else {
		      &logthis(
 "<font color=blue>WARNING: $clientip did not reply challenge</font>");
                      &status('No challenge reply '.$clientip);
                  }
              } else {
		  &logthis(
                    "<font color=blue>WARNING: "
                   ."$clientip failed to initialize: >$remotereq< </font>");
                  &status('No init '.$clientip);
              }
	    } 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

	      &reconlonc("$perlvar{'lonSockDir'}/$hostid{$clientip}");
              &logthis(
       "<font color=green>Established connection: $hostid{$clientip}</font>");
              &status('Will listen to '.$hostid{$clientip});
# ------------------------------------------------------------ Process requests
              while (my $userinput=<$client>) {
                chomp($userinput);
		Debug("Request = $userinput\n");
                &status('Processing '.$hostid{$clientip}.': '.$userinput);
                my $wasenc=0;
                alarm(120);
# ------------------------------------------------------------ See if encrypted
		if ($userinput =~ /^enc/) {
		  if ($cipher) {
                    my ($cmd,$cmdlength,$encinput)=split(/:/,$userinput);
		    $userinput='';
                    for (my $encidx=0;$encidx<length($encinput);$encidx+=16) {
                       $userinput.=
			   $cipher->decrypt(
                            pack("H16",substr($encinput,$encidx,16))
                           );
		    }
		    $userinput=substr($userinput,0,$cmdlength);
                    $wasenc=1;
		}
	      }
	  
# ------------------------------------------------------------- Normal commands
# ------------------------------------------------------------------------ ping
		   if ($userinput =~ /^ping/) {
                       print $client "$perlvar{'lonHostID'}\n";
# ------------------------------------------------------------------------ pong
		   } elsif ($userinput =~ /^pong/) {
                       $reply=reply("ping",$hostid{$clientip});
                       print $client "$perlvar{'lonHostID'}:$reply\n"; 
# ------------------------------------------------------------------------ ekey
		   } elsif ($userinput =~ /^ekey/) {
                       my $buildkey=time.$$.int(rand 100000);
                       $buildkey=~tr/1-6/A-F/;
                       $buildkey=int(rand 100000).$buildkey.int(rand 100000);
                       my $key=$perlvar{'lonHostID'}.$hostid{$clientip};
                       $key=~tr/a-z/A-Z/;
                       $key=~tr/G-P/0-9/;
                       $key=~tr/Q-Z/0-9/;
                       $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
                       $key=substr($key,0,32);
                       my $cipherkey=pack("H32",$key);
                       $cipher=new IDEA $cipherkey;
                       print $client "$buildkey\n"; 
# ------------------------------------------------------------------------ load
		   } elsif ($userinput =~ /^load/) {
                       my $loadavg;
                       {
                          my $loadfile=IO::File->new('/proc/loadavg');
                          $loadavg=<$loadfile>;
                       }
                       $loadavg =~ s/\s.*//g;
                       my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};
		       print $client "$loadpercent\n";
# ----------------------------------------------------------------- currentauth
		   } elsif ($userinput =~ /^currentauth/) {
		     if ($wasenc==1) {
                       my ($cmd,$udom,$uname)=split(/:/,$userinput);
		       my $result = GetAuthType($udom, $uname);
		       if($result eq "nouser") {
			   print $client "unknown_user\n";
		       }
		       else {
			   print $client "$result\n"
		       }
		     } else {
		       print $client "refused\n";
		     }
# ------------------------------------------------------------------------ auth
                   } elsif ($userinput =~ /^auth/) {
		     if ($wasenc==1) {
                       my ($cmd,$udom,$uname,$upass)=split(/:/,$userinput);
                       chomp($upass);
                       $upass=unescape($upass);
                       my $proname=propath($udom,$uname);
                       my $passfilename="$proname/passwd";
                       if (-e $passfilename) {
                          my $pf = IO::File->new($passfilename);
                          my $realpasswd=<$pf>;
                          chomp($realpasswd);
                          my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
                          my $pwdcorrect=0;
                          if ($howpwd eq 'internal') {
			      &Debug("Internal auth");
			      $pwdcorrect=
				  (crypt($upass,$contentpwd) eq $contentpwd);
                          } elsif ($howpwd eq 'unix') {
			      &Debug("Unix auth");
                              if((getpwnam($uname))[1] eq "") { #no such user!
				  $pwdcorrect = 0;
			      } else {
				  $contentpwd=(getpwnam($uname))[1];
				  my $pwauth_path="/usr/local/sbin/pwauth";
				  unless ($contentpwd eq 'x') {
				      $pwdcorrect=
					  (crypt($upass,$contentpwd) eq 
					   $contentpwd);
				  }
		  
			      elsif (-e $pwauth_path) {
				  open PWAUTH, "|$pwauth_path" or
				      die "Cannot invoke authentication";
				  print PWAUTH "$uname\n$upass\n";
				  close PWAUTH;
				  $pwdcorrect=!$?;
			      }
			      }
                          } elsif ($howpwd eq 'krb4') {
                              $null=pack("C",0);
                              unless ($upass=~/$null/) {
                                  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:'.$uname.','.$contentpwd.','.
                &Authen::Krb4::get_err_txt($Authen::Krb4::error));
                                      }
                                  }
                              }
                          } elsif ($howpwd eq 'krb5') {
			      $null=pack("C",0);
			      unless ($upass=~/$null/) {
				  my $krbclient=&Authen::Krb5::parse_name($uname.'@'.$contentpwd);
				  my $krbservice="krbtgt/".$contentpwd."\@".$contentpwd;
				  my $krbserver=&Authen::Krb5::parse_name($krbservice);
				  my $credentials=&Authen::Krb5::cc_default();
				  $credentials->initialize($krbclient);
				  my $krbreturn = 
				    &Authen::Krb5::get_in_tkt_with_password(
				     $krbclient,$krbserver,$upass,$credentials);
#				  unless ($krbreturn) {
#				      &logthis("Krb5 Error: ".
#					       &Authen::Krb5::error());
#				  }
				  $pwdcorrect = ($krbreturn == 1);
			   } else { $pwdcorrect=0; }
                          } elsif ($howpwd eq 'localauth') {
			    $pwdcorrect=&localauth::localauth($uname,$upass,
							      $contentpwd);
			  }
                          if ($pwdcorrect) {
                             print $client "authorized\n";
                          } else {
                             print $client "non_authorized\n";
                          }  
		       } else {
                          print $client "unknown_user\n";
                       }
		     } else {
		       print $client "refused\n";
		     }
# ---------------------------------------------------------------------- passwd
                   } elsif ($userinput =~ /^passwd/) {
		     if ($wasenc==1) {
                       my 
                       ($cmd,$udom,$uname,$upass,$npass)=split(/:/,$userinput);
                       chomp($npass);
                       $upass=&unescape($upass);
                       $npass=&unescape($npass);
		       &Debug("Trying to change password for $uname");
		       my $proname=propath($udom,$uname);
                       my $passfilename="$proname/passwd";
                       if (-e $passfilename) {
			   my $realpasswd;
                          { my $pf = IO::File->new($passfilename);
			    $realpasswd=<$pf>; }
                          chomp($realpasswd);
                          my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
                          if ($howpwd eq 'internal') {
			   &Debug("internal auth");
			   if (crypt($upass,$contentpwd) eq $contentpwd) {
			     my $salt=time;
                             $salt=substr($salt,6,2);
			     my $ncpass=crypt($npass,$salt);
                             { my $pf = IO::File->new(">$passfilename");
 	  		       print $pf "internal:$ncpass\n"; }             
			     &logthis("Result of password change for $uname: pwchange_success");
                             print $client "ok\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 > /home/www/lcpasswd.log");
				 print $pf "$uname\n$npass\n$npass\n";
				 close $pf;
				 my $err = $?;
				 my $result = ($err>0 ? 'pwchange_failure' 
					       : 'ok');
				 &logthis("Result of password change for $uname: ".
					  &lcpasswdstrerror($?));
				 print $client "$result\n";
			     } else {
				 print $client "non_authorized\n";
			     }
			  } else {
                            print $client "auth_mode_error\n";
                          }  
		       } else {
                          print $client "unknown_user\n";
                       }
		     } else {
		       print $client "refused\n";
		     }
# -------------------------------------------------------------------- makeuser
                   } elsif ($userinput =~ /^makeuser/) {
		     &Debug("Make user received");
    	             my $oldumask=umask(0077);
		     if ($wasenc==1) {
                       my 
                       ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
		       &Debug("cmd =".$cmd." $udom =".$udom.
				    " uname=".$uname);
                       chomp($npass);
                       $npass=&unescape($npass);
                       my $proname=propath($udom,$uname);
                       my $passfilename="$proname/passwd";
		       &Debug("Password file created will be:".
				    $passfilename);
                       if (-e $passfilename) {
			   print $client "already_exists\n";
                       } elsif ($udom ne $perlvar{'lonDefDomain'}) {
                           print $client "not_right_domain\n";
                       } else {
                           @fpparts=split(/\//,$proname);
                           $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];
                           $fperror='';
                           for ($i=3;$i<=$#fpparts;$i++) {
                               $fpnow.='/'.$fpparts[$i]; 
                               unless (-e $fpnow) {
				   unless (mkdir($fpnow,0777)) {
                                      $fperror="error: ".($!+0)
					  ." mkdir failed\n";
                                   }
                               }
                           }
                           unless ($fperror) {
			       my $result=&make_passwd_file($uname, $umode,$npass,
							    $passfilename);
			       print $client $result;
                           } else {
                               print $client "$fperror\n";
                           }
                       }
		     } else {
		       print $client "refused\n";
		     }
		     umask($oldumask);
# -------------------------------------------------------------- changeuserauth
                   } elsif ($userinput =~ /^changeuserauth/) {
		       &Debug("Changing authorization");
		      if ($wasenc==1) {
                       my 
		       ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
                       chomp($npass);
		       &Debug("cmd = ".$cmd." domain= ".$udom.
			      "uname =".$uname." umode= ".$umode);
                       $npass=&unescape($npass);
                       my $proname=&propath($udom,$uname);
                       my $passfilename="$proname/passwd";
		       if ($udom ne $perlvar{'lonDefDomain'}) {
                           print $client "not_right_domain\n";
                       } else {
			   my $result=&make_passwd_file($uname, $umode,$npass,
							$passfilename);
			   print $client $result;
                       }
		     } else {
		       print $client "refused\n";
		     }
# ------------------------------------------------------------------------ home
                   } elsif ($userinput =~ /^home/) {
                       my ($cmd,$udom,$uname)=split(/:/,$userinput);
                       chomp($uname);
                       my $proname=propath($udom,$uname);
                       if (-e $proname) {
                          print $client "found\n";
                       } else {
			  print $client "not_found\n";
                       }
# ---------------------------------------------------------------------- update
                   } elsif ($userinput =~ /^update/) {
                       my ($cmd,$fname)=split(/:/,$userinput);
                       my $ownership=ishome($fname);
                       if ($ownership eq 'not_owner') {
                        if (-e $fname) {
                          my ($dev,$ino,$mode,$nlink,
                              $uid,$gid,$rdev,$size,
                              $atime,$mtime,$ctime,
                              $blksize,$blocks)=stat($fname);
                          $now=time;
                          $since=$now-$atime;
                          if ($since>$perlvar{'lonExpire'}) {
                              $reply=
                                    reply("unsub:$fname","$hostid{$clientip}");
                              unlink("$fname");
                          } else {
			     my $transname="$fname.in.transfer";
                             my $remoteurl=
                                    reply("sub:$fname","$hostid{$clientip}");
                             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)");
                             } else {
	                         if ($remoteurl!~/\.meta$/) {
                                  my $ua=new LWP::UserAgent;
                                  my $mrequest=
                                   new HTTP::Request('GET',$remoteurl.'.meta');
                                  my $mresponse=
                                   $ua->request($mrequest,$fname.'.meta');
                                  if ($mresponse->is_error()) {
		                    unlink($fname.'.meta');
                                  }
	                         }
                                 rename($transname,$fname);
			     }
                          }
                          print $client "ok\n";
                        } else {
                          print $client "not_found\n";
                        }
		       } else {
			print $client "rejected\n";
                       }
# -------------------------------------- fetch a user file from a remote server
                   } elsif ($userinput =~ /^fetchuserfile/) {
                      my ($cmd,$fname)=split(/:/,$userinput);
		      my ($udom,$uname,$ufile)=split(/\//,$fname);
                      my $udir=propath($udom,$uname).'/userfiles';
                      unless (-e $udir) { mkdir($udir,0770); }
                       if (-e $udir) {
                       $ufile=~s/^[\.\~]+//;
                       $ufile=~s/\///g;
                       my $transname=$udir.'/'.$ufile;
                       my $remoteurl='http://'.$clientip.'/userfiles/'.$fname;
                             my $response;
                              {
                             my $ua=new LWP::UserAgent;
                             my $request=new HTTP::Request('GET',"$remoteurl");
                             $response=$ua->request($request,$transname);
			      }
                             if ($response->is_error()) {
				 unlink($transname);
                                 my $message=$response->status_line;
                                 &logthis(
                                  "LWP GET: $message for $fname ($remoteurl)");
				 print $client "failed\n";
                             } else {
                                 print $client "ok\n";
                             }
                     } else {
                       print $client "not_home\n";
                     } 
# ------------------------------------------ authenticate access to a user file
                   } elsif ($userinput =~ /^tokenauthuserfile/) {
                       my ($cmd,$fname,$session)=split(/:/,$userinput);
                       chomp($session);
                       $reply='non_auth';
                       if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'.
                                      $session.'.id')) {
                        while ($line=<ENVIN>) {
			   if ($line=~/userfile\.$fname\=/) { $reply='ok'; }
                        }
                        close(ENVIN);
                        print $client $reply."\n";
		       } else {
			print $client "invalid_token\n";
                       }
# ----------------------------------------------------------------- unsubscribe
                   } elsif ($userinput =~ /^unsub/) {
                       my ($cmd,$fname)=split(/:/,$userinput);
                       if (-e $fname) {
			   print $client &unsub($client,$fname,$clientip);
                       } else {
			   print $client "not_found\n";
                       }
# ------------------------------------------------------------------- subscribe
                   } elsif ($userinput =~ /^sub/) {
		       print $client &subscribe($userinput,$clientip);
# ------------------------------------------------------------- current version
                   } elsif ($userinput =~ /^currentversion/) {
                       my ($cmd,$fname)=split(/:/,$userinput);
		       print $client &currentversion($fname)."\n";
# ------------------------------------------------------------------------- log
                   } elsif ($userinput =~ /^log/) {
                       my ($cmd,$udom,$uname,$what)=split(/:/,$userinput);
                       chomp($what);
                       my $proname=propath($udom,$uname);
                       my $now=time;
                       {
			 my $hfh;
			 if ($hfh=IO::File->new(">>$proname/activity.log")) { 
                            print $hfh "$now:$hostid{$clientip}:$what\n";
                            print $client "ok\n"; 
			} else {
                            print $client "error: ".($!+0)
				." IO::File->new Failed\n";
		        }
		       }
# ------------------------------------------------------------------------- put
                   } elsif ($userinput =~ /^put/) {
                      my ($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);
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
                           foreach $pair (@pairs) {
			       ($key,$value)=split(/=/,$pair);
                               $hash{$key}=$value;
                           }
			   if (untie(%hash)) {
                              print $client "ok\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) failed\n";
                           }
                       } else {
                           print $client "error: ".($!)
			       ." tie(GDBM) Failed\n";
                       }
		      } else {
                          print $client "refused\n";
                      }
# -------------------------------------------------------------------- rolesput
                   } elsif ($userinput =~ /^rolesput/) {
		       &Debug("rolesput");
		    if ($wasenc==1) {
                       my ($cmd,$exedom,$exeuser,$udom,$uname,$what)
                          =split(/:/,$userinput);
		       &Debug("cmd = ".$cmd." exedom= ".$exedom.
				    "user = ".$exeuser." udom=".$udom.
				    "what = ".$what);
                       my $namespace='roles';
                       chomp($what);
                       my $proname=propath($udom,$uname);
                       my $now=time;
                       {
			   my $hfh;
			   if (
                             $hfh=IO::File->new(">>$proname/$namespace.hist")
			       ) { 
                                  print $hfh "P:$now:$exedom:$exeuser:$what\n";
                                 }
		       }
                       my @pairs=split(/\&/,$what);
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
                           foreach $pair (@pairs) {
			       ($key,$value)=split(/=/,$pair);
			       &ManagePermissions($key, $udom, $uname,
						  &GetAuthType( $udom, 
								$uname));
                               $hash{$key}=$value;
			       
                           }
			   if (untie(%hash)) {
                              print $client "ok\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
		      } else {
                          print $client "refused\n";
                      }
# ------------------------------------------------------------------------- get
                   } elsif ($userinput =~ /^get/) {
                       my ($cmd,$udom,$uname,$namespace,$what)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       chomp($what);
                       my @queries=split(/\&/,$what);
                       my $proname=propath($udom,$uname);
                       my $qresult='';
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
                           for ($i=0;$i<=$#queries;$i++) {
                               $qresult.="$hash{$queries[$i]}&";
                           }
			   if (untie(%hash)) {
		              $qresult=~s/\&$//;
                              print $client "$qresult\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ------------------------------------------------------------------------ eget
                   } elsif ($userinput =~ /^eget/) {
                       my ($cmd,$udom,$uname,$namespace,$what)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       chomp($what);
                       my @queries=split(/\&/,$what);
                       my $proname=propath($udom,$uname);
                       my $qresult='';
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
                           for ($i=0;$i<=$#queries;$i++) {
                               $qresult.="$hash{$queries[$i]}&";
                           }
			   if (untie(%hash)) {
		              $qresult=~s/\&$//;
                              if ($cipher) {
                                my $cmdlength=length($qresult);
                                $qresult.="         ";
                                my $encqresult='';
                                for 
				(my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
                                 $encqresult.=
                                 unpack("H16",
                                 $cipher->encrypt(substr($qresult,$encidx,8)));
                                }
                                print $client "enc:$cmdlength:$encqresult\n";
			      } else {
			        print $client "error:no_key\n";
                              }
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ------------------------------------------------------------------------- del
                   } elsif ($userinput =~ /^del/) {
                       my ($cmd,$udom,$uname,$namespace,$what)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       chomp($what);
                       my $proname=propath($udom,$uname);
                       my $now=time;
                       unless ($namespace=~/^nohist\_/) {
			   my $hfh;
			   if (
                             $hfh=IO::File->new(">>$proname/$namespace.hist")
			       ) { print $hfh "D:$now:$what\n"; }
		       }
                       my @keys=split(/\&/,$what);
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
                           foreach $key (@keys) {
                               delete($hash{$key});
                           }
			   if (untie(%hash)) {
                              print $client "ok\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ------------------------------------------------------------------------ keys
                   } elsif ($userinput =~ /^keys/) {
                       my ($cmd,$udom,$uname,$namespace)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       my $proname=propath($udom,$uname);
                       my $qresult='';
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
                           foreach $key (keys %hash) {
                               $qresult.="$key&";
                           }
			   if (untie(%hash)) {
		              $qresult=~s/\&$//;
                              print $client "$qresult\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ----------------------------------------------------------------- dumpcurrent
                   } elsif ($userinput =~ /^currentdump/) {
                       my ($cmd,$udom,$uname,$namespace)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       my $qresult='';
                       my $proname=propath($udom,$uname);
                       if (tie(%hash,'GDBM_File',
                               "$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\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ------------------------------------------------------------------------ dump
                   } elsif ($userinput =~ /^dump/) {
                       my ($cmd,$udom,$uname,$namespace,$regexp)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       if (defined($regexp)) {
                          $regexp=&unescape($regexp);
		       } else {
                          $regexp='.';
		       }
                       my $qresult='';
                       my $proname=propath($udom,$uname);
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
                           study($regexp);
                           while (($key,$value) = each(%hash)) {
                               if ($regexp eq '.') {
                                   $qresult.=$key.'='.$value.'&';
                               } else {
                                   my $unescapeKey = &unescape($key);
                                   if (eval('$unescapeKey=~/$regexp/')) {
                                       $qresult.="$key=$value&";
                                   }
                               }
                           }
                           if (untie(%hash)) {
                               chop($qresult);
                               print $client "$qresult\n";
                           } else {
                               print $client "error: ".($!+0)
				   ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ----------------------------------------------------------------------- store
                   } elsif ($userinput =~ /^store/) {
                      my ($cmd,$udom,$uname,$namespace,$rid,$what)
                          =split(/:/,$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:$rid:$what\n"; }
		       }
                       my @pairs=split(/\&/,$what);
                         
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
                           my @previouskeys=split(/&/,$hash{"keys:$rid"});
                           my $key;
                           $hash{"version:$rid"}++;
                           my $version=$hash{"version:$rid"};
                           my $allkeys=''; 
                           foreach $pair (@pairs) {
			       ($key,$value)=split(/=/,$pair);
                               $allkeys.=$key.':';
                               $hash{"$version:$rid:$key"}=$value;
                           }
                           $hash{"$version:$rid:timestamp"}=$now;
                           $allkeys.='timestamp';
                           $hash{"$version:keys:$rid"}=$allkeys;
			   if (untie(%hash)) {
                              print $client "ok\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
		      } else {
                          print $client "refused\n";
                      }
# --------------------------------------------------------------------- restore
                   } elsif ($userinput =~ /^restore/) {
                       my ($cmd,$udom,$uname,$namespace,$rid)
                          =split(/:/,$userinput);
                       $namespace=~s/\//\_/g;
                       $namespace=~s/\W//g;
                       chomp($rid);
                       my $proname=propath($udom,$uname);
                       my $qresult='';
      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
                	   my $version=$hash{"version:$rid"};
                           $qresult.="version=$version&";
                           my $scope;
                           for ($scope=1;$scope<=$version;$scope++) {
			      my $vkeys=$hash{"$scope:keys:$rid"};
                              my @keys=split(/:/,$vkeys);
                              my $key;
                              $qresult.="$scope:keys=$vkeys&";
                              foreach $key (@keys) {
	     $qresult.="$scope:$key=".$hash{"$scope:$rid:$key"}."&";
                              }                                  
                           }
			   if (untie(%hash)) {
		              $qresult=~s/\&$//;
                              print $client "$qresult\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# -------------------------------------------------------------------- chatsend
                   } elsif ($userinput =~ /^chatsend/) {
                       my ($cmd,$cdom,$cnum,$newpost)=split(/\:/,$userinput);
                       &chatadd($cdom,$cnum,$newpost);
                       print $client "ok\n";
# -------------------------------------------------------------------- chatretr
                   } elsif ($userinput =~ /^chatretr/) {
                       my ($cmd,$cdom,$cnum)=split(/\:/,$userinput);
                       my $reply='';
                       foreach (&getchat($cdom,$cnum)) {
			   $reply.=&escape($_).':';
                       }
                       $reply=~s/\:$//;
                       print $client $reply."\n";
# ------------------------------------------------------------------- querysend
                   } elsif ($userinput =~ /^querysend/) {
                       my ($cmd,$query,
			   $arg1,$arg2,$arg3)=split(/\:/,$userinput);
		       $query=~s/\n*$//g;
		       print $client "".
			       sqlreply("$hostid{$clientip}\&$query".
					"\&$arg1"."\&$arg2"."\&$arg3")."\n";
# ------------------------------------------------------------------ queryreply
                   } elsif ($userinput =~ /^queryreply/) {
                       my ($cmd,$id,$reply)=split(/:/,$userinput); 
		       my $store;
                       my $execdir=$perlvar{'lonDaemons'};
                       if ($store=IO::File->new(">$execdir/tmp/$id")) {
			   $reply=~s/\&/\n/g;
			   print $store $reply;
			   close $store;
			   my $store2=IO::File->new(">$execdir/tmp/$id.end");
			   print $store2 "done\n";
			   close $store2;
			   print $client "ok\n";
		       }
		       else {
			   print $client "error: ".($!+0)
			       ." IO::File->new Failed\n";
		       }
# ----------------------------------------------------------------------- idput
                   } elsif ($userinput =~ /^idput/) {
                       my ($cmd,$udom,$what)=split(/:/,$userinput);
                       chomp($what);
                       $udom=~s/\W//g;
                       my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
                       my $now=time;
                       {
			   my $hfh;
			   if (
                             $hfh=IO::File->new(">>$proname.hist")
			       ) { print $hfh "P:$now:$what\n"; }
		       }
                       my @pairs=split(/\&/,$what);
                 if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT,0640)) {
                           foreach $pair (@pairs) {
			       ($key,$value)=split(/=/,$pair);
                               $hash{$key}=$value;
                           }
			   if (untie(%hash)) {
                              print $client "ok\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ----------------------------------------------------------------------- idget
                   } elsif ($userinput =~ /^idget/) {
                       my ($cmd,$udom,$what)=split(/:/,$userinput);
                       chomp($what);
                       $udom=~s/\W//g;
                       my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
                       my @queries=split(/\&/,$what);
                       my $qresult='';
                 if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER,0640)) {
                           for ($i=0;$i<=$#queries;$i++) {
                               $qresult.="$hash{$queries[$i]}&";
                           }
			   if (untie(%hash)) {
		              $qresult=~s/\&$//;
                              print $client "$qresult\n";
                           } else {
                              print $client "error: ".($!+0)
				  ." untie(GDBM) Failed\n";
                           }
                       } else {
                           print $client "error: ".($!+0)
			       ." tie(GDBM) Failed\n";
                       }
# ---------------------------------------------------------------------- tmpput
                   } elsif ($userinput =~ /^tmpput/) {
                       my ($cmd,$what)=split(/:/,$userinput);
		       my $store;
                       $tmpsnum++;
                       my $id=$$.'_'.$clientip.'_'.$tmpsnum;
                       $id=~s/\W/\_/g;
                       $what=~s/\n//g;
                       my $execdir=$perlvar{'lonDaemons'};
                       if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {
			   print $store $what;
			   close $store;
			   print $client "$id\n";
		       }
		       else {
			   print $client "error: ".($!+0)
			       ."IO::File->new Failed\n";
		       }

# ---------------------------------------------------------------------- tmpget
                   } elsif ($userinput =~ /^tmpget/) {
                       my ($cmd,$id)=split(/:/,$userinput);
                       chomp($id);
                       $id=~s/\W/\_/g;
                       my $store;
                       my $execdir=$perlvar{'lonDaemons'};
                       if ($store=IO::File->new("$execdir/tmp/$id.tmp")) {
                           my $reply=<$store>;
			   print $client "$reply\n";
                           close $store;
		       }
		       else {
			   print $client "error: ".($!+0)
			       ."IO::File->new Failed\n";
		       }

# ---------------------------------------------------------------------- tmpdel
                   } elsif ($userinput =~ /^tmpdel/) {
                       my ($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\n";
		       }
# -------------------------------------------------------------------------- ls
                   } elsif ($userinput =~ /^ls/) {
                       my ($cmd,$ulsdir)=split(/:/,$userinput);
                       my $ulsout='';
                       my $ulsfn;
                       if (-e $ulsdir) {
                           if(-d $ulsdir) {
                               if (opendir(LSDIR,$ulsdir)) {
                                   while ($ulsfn=readdir(LSDIR)) {
                                       my @ulsstats=stat($ulsdir.'/'.$ulsfn);
                                       $ulsout.=$ulsfn.'&'.
                                                join('&',@ulsstats).':';
                                   }
                                   closedir(LSDIR);
                               }
                           } else {
                               my @ulsstats=stat($ulsdir);
                               $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
                           }
                       } else {
                          $ulsout='no_such_dir';
                       }
                       if ($ulsout eq '') { $ulsout='empty'; }
                       print $client "$ulsout\n";
# ------------------------------------------------------------------ Hanging up
                   } elsif (($userinput =~ /^exit/) ||
                            ($userinput =~ /^init/)) {
                       &logthis(
      "Client $clientip ($hostid{$clientip}) hanging up: $userinput");
                       print $client "bye\n";
                       $client->close();
		       last;
# ------------------------------------------------------------- unknown command
                   } else {
                       # unknown command
                       print $client "unknown_cmd\n";
                   }
# -------------------------------------------------------------------- complete
		   alarm(0);
                   &status('Listening to '.$hostid{$clientip});
	       }
# --------------------------------------------- client unknown or fishy, refuse
            } else {
	        print $client "refused\n";
                $client->close();
                &logthis("<font color=blue>WARNING: "
                ."Rejected client $clientip, closing connection</font>");
            }
	}             

# =============================================================================
       
	&logthis("<font color=red>CRITICAL: "
		 ."Disconnect from $clientip ($hostid{$clientip})</font>");    


        # this exit is VERY important, otherwise the child will become
        # a producer of more and more children, forking yourself into
        # process death.
        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 = shift;
    my $domain  = shift;
    my $user    = shift;
    my $authtype= shift;

    # See if the request is of the form /$domain/_au

    if($request =~ /^(\/$domain\/_au)$/) { # It's an author rolesput...
	my $execdir = $perlvar{'lonDaemons'};
	my $userhome= "/home/$user" ;
	Debug("system $execdir/lchtmldir $userhome $system $authtype");
	system("$execdir/lchtmldir $userhome $user $authtype");
    }
}
#
#   GetAuthType - Determines the authorization type of a user in a domain.

#     Returns the authorization type or nouser if there is no such user.
#
sub GetAuthType 
{
    my $domain = shift;
    my $user   = shift;

    Debug("GetAuthType( $domain, $user ) \n");
    my $proname    = &propath($domain, $user); 
    my $passwdfile = "$proname/passwd";
    if( -e $passwdfile ) {
	my $pf = IO::File->new($passwdfile);
	my $realpassword = <$pf>;
	chomp($realpassword);
	Debug("Password info = $realpassword\n");
	my ($authtype, $contentpwd) = split(/:/, $realpassword);
	Debug("Authtype = $authtype, content = $contentpwd\n");
	my $availinfo = '';
	if($authtype eq 'krb4' or $authtype eq 'krb5') {
	    $availinfo = $contentpwd;
	}

	return "$authtype:$availinfo";
    }
    else {
	Debug("Returning nouser");
	return "nouser";
    }
}

sub addline {
    my ($fname,$hostid,$ip,$newline)=@_;
    my $contents;
    my $found=0;
    my $expr='^'.$hostid.':'.$ip.':';
    $expr =~ s/\./\\\./g;
    if ($sh=IO::File->new("$fname.subscription")) {
	while (my $subline=<$sh>) {
	    if ($subline !~ /$expr/) {$contents.= $subline;} else {$found=1;}
	}
	$sh->close();
    }
    $sh=IO::File->new(">$fname.subscription");
    if ($contents) { print $sh $contents; }
    if ($newline) { print $sh $newline; }
    $sh->close();
    return $found;
}

sub getchat {
    my ($cdom,$cname)=@_;
    my %hash;
    my $proname=&propath($cdom,$cname);
    my @entries=();
    if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db",
	    &GDBM_READER(),0640)) {
	@entries=map { $_.':'.$hash{$_} } sort keys %hash;
	untie %hash;
    }
    return @entries;
}

sub chatadd {
    my ($cdom,$cname,$newchat)=@_;
    my %hash;
    my $proname=&propath($cdom,$cname);
    my @entries=();
    if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db",
	    &GDBM_WRCREAT(),0640)) {
	@entries=map { $_.':'.$hash{$_} } sort keys %hash;
	my $time=time;
	my ($lastid)=($entries[$#entries]=~/^(\w+)\:/);
	my ($thentime,$idnum)=split(/\_/,$lastid);
	my $newid=$time.'_000000';
	if ($thentime==$time) {
	    $idnum=~s/^0+//;
	    $idnum++;
	    $idnum=substr('000000'.$idnum,-6,6);
	    $newid=$time.'_'.$idnum;
	}
	$hash{$newid}=$newchat;
	my $expired=$time-3600;
	foreach (keys %hash) {
	    my ($thistime)=($_=~/(\d+)\_/);
	    if ($thistime<$expired) {
		delete $hash{$_};
	    }
	}
	untie %hash;
    }
}

sub unsub {
    my ($fname,$clientip)=@_;
    my $result;
    if (unlink("$fname.$hostid{$clientip}")) {
	$result="ok\n";
    } else {
	$result="not_subscribed\n";
    }
    if (-e "$fname.subscription") {
	my $found=&addline($fname,$hostid{$clientip},$clientip,'');
	if ($found) { $result="ok\n"; }
    } else {
	if ($result != "ok\n") { $result="not_subscribed\n"; }
    }
    return $result;
}

sub currentversion {
    my $fname=shift;
    my $version=-1;
    my $ulsdir='';
    if ($fname=~/^(.+)\/[^\/]+$/) {
       $ulsdir=$1;
    }
    $fname=~s/\.\d+\.(\w+(?:\.meta)*)$/\.$1/;
    $fname=~s/\.(\w+(?:\.meta)*)$/\.\(\\d\+\)\.$1\$/;

    if (-e $fname) { $version=1; }
    if (-e $ulsdir) {
       if(-d $ulsdir) {
          if (opendir(LSDIR,$ulsdir)) {
             while ($ulsfn=readdir(LSDIR)) {
# see if this is a regular file (ignore links produced earlier)
                 my $thisfile=$ulsdir.'/'.$ulsfn;
                 unless (-l $thisfile) {
		    if ($thisfile=~/$fname/) {
		        if ($1>$version) { $version=$1; }
                    }
		 }
             }
             closedir(LSDIR);
             $version++;
          }
      }
   }
   return $version;
}

sub thisversion {
    my $fname=shift;
    my $version=-1;
    if ($fname=~/\.(\d+)\.\w+(?:\.meta)*$/) {
	$version=$1;
    }
    return $version;
}

sub subscribe {
    my ($userinput,$clientip)=@_;
    my $result;
    my ($cmd,$fname)=split(/:/,$userinput);
    my $ownership=&ishome($fname);
    if ($ownership eq 'owner') {
# explitly asking for the current version?
        unless (-e $fname) {
            my $currentversion=&currentversion($fname);
	    if (&thisversion($fname)==$currentversion) {
                if ($fname=~/^(.+)\.\d+\.(\w+(?:\.meta)*)$/) {
		    my $root=$1;
                    my $extension=$2;
                    symlink($root.'.'.$extension,
                            $root.'.'.$currentversion.'.'.$extension);
                    unless ($extension=~/\.meta$/) {
                       symlink($root.'.'.$extension.'.meta',
                            $root.'.'.$currentversion.'.'.$extension.'.meta');
		    }
                }
            }
        }
	if (-e $fname) {
	    if (-d $fname) {
		$result="directory\n";
	    } else {
		if (-e "$fname.$hostid{$clientip}") {&unsub($fname,$clientip);}
		$now=time;
		my $found=&addline($fname,$hostid{$clientip},$clientip,
				   "$hostid{$clientip}:$clientip:$now\n");
		if ($found) { $result="$fname\n"; }
		# if they were subscribed to only meta data, delete that
                # subscription, when you subscribe to a file you also get
                # the metadata
		unless ($fname=~/\.meta$/) { &unsub("$fname.meta",$clientip); }
		$fname=~s/\/home\/httpd\/html\/res/raw/;
		$fname="http://$thisserver/".$fname;
		$result="$fname\n";
	    }
	} else {
	    $result="not_found\n";
	}
    } else {
	$result="rejected\n";
    }
    return $result;
}

sub make_passwd_file {
    my ($uname, $umode,$npass,$passfilename)=@_;
    my $result="ok\n";
    if ($umode eq 'krb4' or $umode eq 'krb5') {
	{
	    my $pf = IO::File->new(">$passfilename");
	    print $pf "$umode:$npass\n";
	}
    } elsif ($umode eq 'internal') {
	my $salt=time;
	$salt=substr($salt,6,2);
	my $ncpass=crypt($npass,$salt);
	{
	    &Debug("Creating internal auth");
	    my $pf = IO::File->new(">$passfilename");
	    print $pf "internal:$ncpass\n"; 
	}
    } elsif ($umode eq 'localauth') {
	{
	    my $pf = IO::File->new(">$passfilename");
	    print $pf "localauth:$npass\n";
	}
    } elsif ($umode eq 'unix') {
	{
	    my $execpath="$perlvar{'lonDaemons'}/"."lcuseradd";
	    {
		&Debug("Executing external: ".$execpath);
		&Debug("user  = ".$uname.", Password =". $npass);
		my $se = IO::File->new("|$execpath > /home/www/lcuseradd.log");
		print $se "$uname\n";
		print $se "$npass\n";
		print $se "$npass\n";
	    }
	    my $useraddok = $?;
	    if($useraddok > 0) {
		&logthis("Failed lcuseradd: ".&lcuseraddstrerror($useraddok));
	    }
	    my $pf = IO::File->new(">$passfilename");
	    print $pf "unix:\n";
	}
    } elsif ($umode eq 'none') {
	{
	    my $pf = IO::File->new(">$passfilename");
	    print $pf "none:\n";
	}
    } else {
	$result="auth_mode_error\n";
    }
    return $result;
}

# ----------------------------------- POD (plain old documentation, CPAN style)

=head1 NAME

lond - "LON Daemon" Server (port "LOND" 5663)

=head1 SYNOPSIS

Usage: B<lond>

Should only be run as user=www.  This is a command-line script which
is invoked by B<loncron>.  There is no expectation that a typical user
will manually start B<lond> from the command-line.  (In other words,
DO NOT START B<lond> YOURSELF.)

=head1 DESCRIPTION

There are two characteristics associated with the running of B<lond>,
PROCESS MANAGEMENT (starting, stopping, handling child processes)
and SERVER-SIDE ACTIVITIES (password authentication, user creation,
subscriptions, etc).  These are described in two large
sections below.

B<PROCESS MANAGEMENT>

Preforker - server who forks first. Runs as a daemon. HUPs.
Uses IDEA encryption

B<lond> forks off children processes that correspond to the other servers
in the network.  Management of these processes can be done at the
parent process level or the child process level.

B<logs/lond.log> is the location of log messages.

The process management is now explained in terms of linux shell commands,
subroutines internal to this code, and signal assignments:

=over 4

=item *

PID is stored in B<logs/lond.pid>

This is the process id number of the parent B<lond> process.

=item *

SIGTERM and SIGINT

Parent signal assignment:
 $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;

Child signal assignment:
 $SIG{INT}  = 'DEFAULT'; (and SIGTERM is DEFAULT also)
(The child dies and a SIGALRM is sent to parent, awaking parent from slumber
 to restart a new child.)

Command-line invocations:
 B<kill> B<-s> SIGTERM I<PID>
 B<kill> B<-s> SIGINT I<PID>

Subroutine B<HUNTSMAN>:
 This is only invoked for the B<lond> parent I<PID>.
This kills all the children, and then the parent.
The B<lonc.pid> file is cleared.

=item *

SIGHUP

Current bug:
 This signal can only be processed the first time
on the parent process.  Subsequent SIGHUP signals
have no effect.

Parent signal assignment:
 $SIG{HUP}  = \&HUPSMAN;

Child signal assignment:
 none (nothing happens)

Command-line invocations:
 B<kill> B<-s> SIGHUP I<PID>

Subroutine B<HUPSMAN>:
 This is only invoked for the B<lond> parent I<PID>,
This kills all the children, and then the parent.
The B<lond.pid> file is cleared.

=item *

SIGUSR1

Parent signal assignment:
 $SIG{USR1} = \&USRMAN;

Child signal assignment:
 $SIG{USR1}= \&logstatus;

Command-line invocations:
 B<kill> B<-s> SIGUSR1 I<PID>

Subroutine B<USRMAN>:
 When invoked for the B<lond> parent I<PID>,
SIGUSR1 is sent to all the children, and the status of
each connection is logged.

=item *

SIGCHLD

Parent signal assignment:
 $SIG{CHLD} = \&REAPER;

Child signal assignment:
 none

Command-line invocations:
 B<kill> B<-s> SIGCHLD I<PID>

Subroutine B<REAPER>:
 This is only invoked for the B<lond> parent I<PID>.
Information pertaining to the child is removed.
The socket port is cleaned up.

=back

B<SERVER-SIDE ACTIVITIES>

Server-side information can be accepted in an encrypted or non-encrypted
method.

=over 4

=item ping

Query a client in the hosts.tab table; "Are you there?"

=item pong

Respond to a ping query.

=item ekey

Read in encrypted key, make cipher.  Respond with a buildkey.

=item load

Respond with CPU load based on a computation upon /proc/loadavg.

=item currentauth

Reply with current authentication information (only over an
encrypted channel).

=item auth

Only over an encrypted channel, reply as to whether a user's
authentication information can be validated.

=item passwd

Allow for a password to be set.

=item makeuser

Make a user.

=item passwd

Allow for authentication mechanism and password to be changed.

=item home

Respond to a question "are you the home for a given user?"

=item update

Update contents of a subscribed resource.

=item unsubscribe

The server is unsubscribing from a resource.

=item subscribe

The server is subscribing to a resource.

=item log

Place in B<logs/lond.log>

=item put

stores hash in namespace

=item rolesput

put a role into a user's environment

=item get

returns hash with keys from array
reference filled in from namespace

=item eget

returns hash with keys from array
reference filled in from namesp (encrypts the return communication)

=item rolesget

get a role from a user's environment

=item del

deletes keys out of array from namespace

=item keys

returns namespace keys

=item dump

dumps the complete (or key matching regexp) namespace into a hash

=item store

stores hash permanently
for this url; hashref needs to be given and should be a \%hashname; the
remaining args aren't required and if they aren't passed or are '' they will
be derived from the ENV

=item restore

returns a hash for a given url

=item querysend

Tells client about the lonsql process that has been launched in response
to a sent query.

=item queryreply

Accept information from lonsql and make appropriate storage in temporary
file space.

=item idput

Defines usernames as corresponding to IDs.  (These "IDs" are unique identifiers
for each student, defined perhaps by the institutional Registrar.)

=item idget

Returns usernames corresponding to IDs.  (These "IDs" are unique identifiers
for each student, defined perhaps by the institutional Registrar.)

=item tmpput

Accept and store information in temporary space.

=item tmpget

Send along temporarily stored information.

=item ls

List part of a user's directory.

=item Hanging up (exit or init)

What to do when a client tells the server that they (the client)
are leaving the network.

=item unknown command

If B<lond> is sent an unknown command (not in the list above),
it replys to the client "unknown_cmd".

=item UNKNOWN CLIENT

If the anti-spoofing algorithm cannot verify the client,
the client is rejected (with a "refused" message sent
to the client, and the connection is closed.

=back

=head1 PREREQUISITES

IO::Socket
IO::File
Apache::File
Symbol
POSIX
Crypt::IDEA
LWP::UserAgent()
GDBM_File
Authen::Krb4
Authen::Krb5

=head1 COREQUISITES

=head1 OSNAMES

linux

=head1 SCRIPT CATEGORIES

Server/Process

=cut

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>