File:  [LON-CAPA] / loncom / lond
Revision 1.81: download - view: text, annotated - select for diffs
Fri May 17 14:03:04 2002 UTC (21 years, 11 months ago) by matthew
Branches: MAIN
CVS tags: HEAD
Replaced access.conf with loncapa_apache.conf.

    1: #!/usr/bin/perl
    2: # The LearningOnline Network
    3: # lond "LON Daemon" Server (port "LOND" 5663)
    4: #
    5: # $Id: lond,v 1.81 2002/05/17 14:03:04 matthew Exp $
    6: #
    7: # Copyright Michigan State University Board of Trustees
    8: #
    9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
   10: #
   11: # LON-CAPA is free software; you can redistribute it and/or modify
   12: # it under the terms of the GNU General Public License as published by
   13: # the Free Software Foundation; either version 2 of the License, or
   14: # (at your option) any later version.
   15: #
   16: # LON-CAPA is distributed in the hope that it will be useful,
   17: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   19: # GNU General Public License for more details.
   20: #
   21: # You should have received a copy of the GNU General Public License
   22: # along with LON-CAPA; if not, write to the Free Software
   23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   24: #
   25: # /home/httpd/html/adm/gpl.txt
   26: #
   27: # http://www.lon-capa.org/
   28: #
   29: # 5/26/99,6/4,6/10,6/11,6/14,6/15,6/26,6/28,6/30,
   30: # 7/8,7/9,7/10,7/12,7/17,7/19,9/21,
   31: # 10/7,10/8,10/9,10/11,10/13,10/15,11/4,11/16,
   32: # 12/7,12/15,01/06,01/11,01/12,01/14,2/8,
   33: # 03/07,05/31 Gerd Kortemeyer
   34: # 06/26 Scott Harrison
   35: # 06/29,06/30,07/14,07/15,07/17,07/20,07/25,09/18 Gerd Kortemeyer
   36: # 12/05 Scott Harrison
   37: # 12/05,12/13,12/29 Gerd Kortemeyer
   38: # YEAR=2001
   39: # Jan 01 Scott Harrison
   40: # 02/12 Gerd Kortemeyer
   41: # 03/15 Scott Harrison
   42: # 03/24 Gerd Kortemeyer
   43: # 04/02 Scott Harrison
   44: # 05/11,05/28,08/30 Gerd Kortemeyer
   45: # 9/30,10/22,11/13,11/15,11/16 Scott Harrison
   46: # 11/26,11/27 Gerd Kortemeyer
   47: # 12/20 Scott Harrison
   48: # 12/22 Gerd Kortemeyer
   49: # YEAR=2002
   50: # 01/20/02,02/05 Gerd Kortemeyer
   51: # 02/05 Guy Albertelli
   52: # 02/07 Scott Harrison
   53: # 02/12 Gerd Kortemeyer
   54: # 02/19 Matthew Hall
   55: # 02/25 Gerd Kortemeyer
   56: # 05/11 Scott Harrison
   57: ###
   58: 
   59: # based on "Perl Cookbook" ISBN 1-56592-243-3
   60: # preforker - server who forks first
   61: # runs as a daemon
   62: # HUPs
   63: # uses IDEA encryption
   64: 
   65: use lib '/home/httpd/lib/perl/';
   66: use LONCAPA::Configuration;
   67: 
   68: use IO::Socket;
   69: use IO::File;
   70: use Apache::File;
   71: use Symbol;
   72: use POSIX;
   73: use Crypt::IDEA;
   74: use LWP::UserAgent();
   75: use GDBM_File;
   76: use Authen::Krb4;
   77: use lib '/home/httpd/lib/perl/';
   78: use localauth;
   79: 
   80: my $DEBUG = 0;		       # Non zero to enable debug log entries.
   81: 
   82: my $status='';
   83: my $lastlog='';
   84: 
   85: # grabs exception and records it to log before exiting
   86: sub catchexception {
   87:     my ($error)=@_;
   88:     $SIG{'QUIT'}='DEFAULT';
   89:     $SIG{__DIE__}='DEFAULT';
   90:     &logthis("<font color=red>CRITICAL: "
   91:      ."ABNORMAL EXIT. Child $$ for server $wasserver died through "
   92:      ."a crash with this error msg->[$error]</font>");
   93:     &logthis('Famous last words: '.$status.' - '.$lastlog);
   94:     if ($client) { print $client "error: $error\n"; }
   95:     $server->close();
   96:     die($error);
   97: }
   98: 
   99: sub timeout {
  100:     &logthis("<font color=ref>CRITICAL: TIME OUT ".$$."</font>");
  101:     &catchexception('Timeout');
  102: }
  103: # -------------------------------- Set signal handlers to record abnormal exits
  104: 
  105: $SIG{'QUIT'}=\&catchexception;
  106: $SIG{__DIE__}=\&catchexception;
  107: 
  108: # ---------------------------------- Read loncapa_apache.conf and loncapa.conf
  109: &status("Read loncapa_apache.conf and loncapa.conf");
  110: my $perlvarref=LONCAPA::Configuration::read_conf('loncapa_apache.conf',
  111:                                                  'loncapa.conf');
  112: my %perlvar=%{$perlvarref};
  113: undef $perlvarref;
  114: 
  115: # ----------------------------- Make sure this process is running from user=www
  116: my $wwwid=getpwnam('www');
  117: if ($wwwid!=$<) {
  118:    $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
  119:    $subj="LON: $perlvar{'lonHostID'} User ID mismatch";
  120:    system("echo 'User ID mismatch.  lond must be run as user www.' |\
  121:  mailto $emailto -s '$subj' > /dev/null");
  122:    exit 1;
  123: }
  124: 
  125: # --------------------------------------------- Check if other instance running
  126: 
  127: my $pidfile="$perlvar{'lonDaemons'}/logs/lond.pid";
  128: 
  129: if (-e $pidfile) {
  130:    my $lfh=IO::File->new("$pidfile");
  131:    my $pide=<$lfh>;
  132:    chomp($pide);
  133:    if (kill 0 => $pide) { die "already running"; }
  134: }
  135: 
  136: $PREFORK=4; # number of children to maintain, at least four spare
  137: 
  138: # ------------------------------------------------------------- Read hosts file
  139: 
  140: open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
  141: 
  142: while ($configline=<CONFIG>) {
  143:     my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
  144:     chomp($ip); $ip=~s/\D+$//;
  145:     $hostid{$ip}=$id;
  146:     if ($id eq $perlvar{'lonHostID'}) { $thisserver=$name; }
  147:     $PREFORK++;
  148: }
  149: close(CONFIG);
  150: 
  151: # establish SERVER socket, bind and listen.
  152: $server = IO::Socket::INET->new(LocalPort => $perlvar{'londPort'},
  153:                                 Type      => SOCK_STREAM,
  154:                                 Proto     => 'tcp',
  155:                                 Reuse     => 1,
  156:                                 Listen    => 10 )
  157:   or die "making socket: $@\n";
  158: 
  159: # --------------------------------------------------------- Do global variables
  160: 
  161: # global variables
  162: 
  163: $MAX_CLIENTS_PER_CHILD  = 50;        # number of clients each child should 
  164:                                     # process
  165: %children               = ();       # keys are current child process IDs
  166: $children               = 0;        # current number of children
  167: 
  168: sub REAPER {                        # takes care of dead children
  169:     $SIG{CHLD} = \&REAPER;
  170:     my $pid = wait;
  171:     if (defined($children{$pid})) {
  172: 	&logthis("Child $pid died");
  173: 	$children --;
  174: 	delete $children{$pid};
  175:     } else {
  176: 	&logthis("Unknown Child $pid died");
  177:     }
  178: }
  179: 
  180: sub HUNTSMAN {                      # signal handler for SIGINT
  181:     local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
  182:     kill 'INT' => keys %children;
  183:     &logthis("Free socket: ".shutdown($server,2)); # free up socket
  184:     my $execdir=$perlvar{'lonDaemons'};
  185:     unlink("$execdir/logs/lond.pid");
  186:     &logthis("<font color=red>CRITICAL: Shutting down</font>");
  187:     exit;                           # clean up with dignity
  188: }
  189: 
  190: sub HUPSMAN {                      # signal handler for SIGHUP
  191:     local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children
  192:     kill 'INT' => keys %children;
  193:     &logthis("Free socket: ".shutdown($server,2)); # free up socket
  194:     &logthis("<font color=red>CRITICAL: Restarting</font>");
  195:     unlink("$execdir/logs/lond.pid");
  196:     my $execdir=$perlvar{'lonDaemons'};
  197:     exec("$execdir/lond");         # here we go again
  198: }
  199: 
  200: sub checkchildren {
  201:     &initnewstatus();
  202:     &logstatus();
  203:     &logthis('Going to check on the children');
  204:     $docdir=$perlvar{'lonDocRoot'};
  205:     foreach (sort keys %children) {
  206: 	sleep 1;
  207:         unless (kill 'USR1' => $_) {
  208: 	    &logthis ('Child '.$_.' is dead');
  209:             &logstatus($$.' is dead');
  210:         } 
  211:     }
  212:     sleep 5;
  213:     foreach (sort keys %children) {
  214:         unless (-e "$docdir/lon-status/londchld/$_.txt") {
  215: 	    &logthis('Child '.$_.' did not respond');
  216: 	    kill 9 => $_;
  217: 	    $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
  218: 	    $subj="LON: $perlvar{'lonHostID'} killed lond process $_";
  219: 	    my $result=`echo 'Killed lond process $_.' | mailto $emailto -s '$subj' > /dev/null`;
  220: 	    $execdir=$perlvar{'lonDaemons'};
  221: 	    $result=`/bin/cp $execdir/logs/lond.log $execdir/logs/lond.log.$_`
  222:         }
  223:     }
  224: }
  225: 
  226: # --------------------------------------------------------------------- Logging
  227: 
  228: sub logthis {
  229:     my $message=shift;
  230:     my $execdir=$perlvar{'lonDaemons'};
  231:     my $fh=IO::File->new(">>$execdir/logs/lond.log");
  232:     my $now=time;
  233:     my $local=localtime($now);
  234:     $lastlog=$local.': '.$message;
  235:     print $fh "$local ($$): $message\n";
  236: }
  237: 
  238: # ------------------------- Conditional log if $DEBUG true.
  239: sub Debug {
  240:     my $message = shift;
  241:     if($DEBUG) {
  242: 	&logthis($message);
  243:     }
  244: }
  245: # ------------------------------------------------------------------ Log status
  246: 
  247: sub logstatus {
  248:     my $docdir=$perlvar{'lonDocRoot'};
  249:     {
  250:     my $fh=IO::File->new(">>$docdir/lon-status/londstatus.txt");
  251:     print $fh $$."\t".$status."\t".$lastlog."\n";
  252:     $fh->close();
  253:     }
  254:     {
  255: 	my $fh=IO::File->new(">$docdir/lon-status/londchld/$$.txt");
  256:         print $fh $status."\n".$lastlog."\n".time;
  257:         $fh->close();
  258:     }
  259: }
  260: 
  261: sub initnewstatus {
  262:     my $docdir=$perlvar{'lonDocRoot'};
  263:     my $fh=IO::File->new(">$docdir/lon-status/londstatus.txt");
  264:     my $now=time;
  265:     my $local=localtime($now);
  266:     print $fh "LOND status $local - parent $$\n\n";
  267:     opendir(DIR,"$docdir/lon-status/londchld");
  268:     while ($filename=readdir(DIR)) {
  269:         unlink("$docdir/lon-status/londchld/$filename");
  270:     }
  271:     closedir(DIR);
  272: }
  273: 
  274: # -------------------------------------------------------------- Status setting
  275: 
  276: sub status {
  277:     my $what=shift;
  278:     my $now=time;
  279:     my $local=localtime($now);
  280:     $status=$local.': '.$what;
  281: }
  282: 
  283: # -------------------------------------------------------- Escape Special Chars
  284: 
  285: sub escape {
  286:     my $str=shift;
  287:     $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
  288:     return $str;
  289: }
  290: 
  291: # ----------------------------------------------------- Un-Escape Special Chars
  292: 
  293: sub unescape {
  294:     my $str=shift;
  295:     $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
  296:     return $str;
  297: }
  298: 
  299: # ----------------------------------------------------------- Send USR1 to lonc
  300: 
  301: sub reconlonc {
  302:     my $peerfile=shift;
  303:     &logthis("Trying to reconnect for $peerfile");
  304:     my $loncfile="$perlvar{'lonDaemons'}/logs/lonc.pid";
  305:     if (my $fh=IO::File->new("$loncfile")) {
  306: 	my $loncpid=<$fh>;
  307:         chomp($loncpid);
  308:         if (kill 0 => $loncpid) {
  309: 	    &logthis("lonc at pid $loncpid responding, sending USR1");
  310:             kill USR1 => $loncpid;
  311:             sleep 5;
  312:             if (-e "$peerfile") { return; }
  313:             &logthis("$peerfile still not there, give it another try");
  314:             sleep 10;
  315:             if (-e "$peerfile") { return; }
  316:             &logthis(
  317:  "<font color=blue>WARNING: $peerfile still not there, giving up</font>");
  318:         } else {
  319: 	    &logthis(
  320:               "<font color=red>CRITICAL: "
  321:              ."lonc at pid $loncpid not responding, giving up</font>");
  322:         }
  323:     } else {
  324:       &logthis('<font color=red>CRITICAL: lonc not running, giving up</font>');
  325:     }
  326: }
  327: 
  328: # -------------------------------------------------- Non-critical communication
  329: 
  330: sub subreply {
  331:     my ($cmd,$server)=@_;
  332:     my $peerfile="$perlvar{'lonSockDir'}/$server";
  333:     my $sclient=IO::Socket::UNIX->new(Peer    =>"$peerfile",
  334:                                       Type    => SOCK_STREAM,
  335:                                       Timeout => 10)
  336:        or return "con_lost";
  337:     print $sclient "$cmd\n";
  338:     my $answer=<$sclient>;
  339:     chomp($answer);
  340:     if (!$answer) { $answer="con_lost"; }
  341:     return $answer;
  342: }
  343: 
  344: sub reply {
  345:   my ($cmd,$server)=@_;
  346:   my $answer;
  347:   if ($server ne $perlvar{'lonHostID'}) { 
  348:     $answer=subreply($cmd,$server);
  349:     if ($answer eq 'con_lost') {
  350: 	$answer=subreply("ping",$server);
  351:         if ($answer ne $server) {
  352: 	    &logthis("sub reply: answer != server");
  353:            &reconlonc("$perlvar{'lonSockDir'}/$server");
  354:         }
  355:         $answer=subreply($cmd,$server);
  356:     }
  357:   } else {
  358:     $answer='self_reply';
  359:   } 
  360:   return $answer;
  361: }
  362: 
  363: # -------------------------------------------------------------- Talk to lonsql
  364: 
  365: sub sqlreply {
  366:     my ($cmd)=@_;
  367:     my $answer=subsqlreply($cmd);
  368:     if ($answer eq 'con_lost') { $answer=subsqlreply($cmd); }
  369:     return $answer;
  370: }
  371: 
  372: sub subsqlreply {
  373:     my ($cmd)=@_;
  374:     my $unixsock="mysqlsock";
  375:     my $peerfile="$perlvar{'lonSockDir'}/$unixsock";
  376:     my $sclient=IO::Socket::UNIX->new(Peer    =>"$peerfile",
  377:                                       Type    => SOCK_STREAM,
  378:                                       Timeout => 10)
  379:        or return "con_lost";
  380:     print $sclient "$cmd\n";
  381:     my $answer=<$sclient>;
  382:     chomp($answer);
  383:     if (!$answer) { $answer="con_lost"; }
  384:     return $answer;
  385: }
  386: 
  387: # -------------------------------------------- Return path to profile directory
  388: 
  389: sub propath {
  390:     my ($udom,$uname)=@_;
  391:     $udom=~s/\W//g;
  392:     $uname=~s/\W//g;
  393:     my $subdir=$uname.'__';
  394:     $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
  395:     my $proname="$perlvar{'lonUsersDir'}/$udom/$subdir/$uname";
  396:     return $proname;
  397: } 
  398: 
  399: # --------------------------------------- Is this the home server of an author?
  400: 
  401: sub ishome {
  402:     my $author=shift;
  403:     $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
  404:     my ($udom,$uname)=split(/\//,$author);
  405:     my $proname=propath($udom,$uname);
  406:     if (-e $proname) {
  407: 	return 'owner';
  408:     } else {
  409:         return 'not_owner';
  410:     }
  411: }
  412: 
  413: # ======================================================= Continue main program
  414: # ---------------------------------------------------- Fork once and dissociate
  415: 
  416: $fpid=fork;
  417: exit if $fpid;
  418: die "Couldn't fork: $!" unless defined ($fpid);
  419: 
  420: POSIX::setsid() or die "Can't start new session: $!";
  421: 
  422: # ------------------------------------------------------- Write our PID on disk
  423: 
  424: $execdir=$perlvar{'lonDaemons'};
  425: open (PIDSAVE,">$execdir/logs/lond.pid");
  426: print PIDSAVE "$$\n";
  427: close(PIDSAVE);
  428: &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");
  429: &status('Starting');
  430: 
  431: # ------------------------------------------------------- Now we are on our own
  432:     
  433: # Fork off our children.
  434: for (1 .. $PREFORK) {
  435:     make_new_child();
  436: }
  437: 
  438: # ----------------------------------------------------- Install signal handlers
  439: 
  440: &status('Forked children');
  441: 
  442: $SIG{CHLD} = \&REAPER;
  443: $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
  444: $SIG{HUP}  = \&HUPSMAN;
  445: $SIG{USR1} = \&checkchildren;
  446: 
  447: # And maintain the population.
  448: while (1) {
  449:     &status('Sleeping');
  450:     sleep;                          # wait for a signal (i.e., child's death)
  451:     &logthis('Woke up');
  452:     &status('Woke up');
  453:     for ($i = $children; $i < $PREFORK; $i++) {
  454:         make_new_child();           # top up the child pool
  455:     }
  456: }
  457: 
  458: sub make_new_child {
  459:     my $pid;
  460:     my $cipher;
  461:     my $sigset;
  462:     &logthis("Attempting to start child");    
  463:     # block signal for fork
  464:     $sigset = POSIX::SigSet->new(SIGINT);
  465:     sigprocmask(SIG_BLOCK, $sigset)
  466:         or die "Can't block SIGINT for fork: $!\n";
  467:     
  468:     die "fork: $!" unless defined ($pid = fork);
  469:     
  470:     if ($pid) {
  471:         # Parent records the child's birth and returns.
  472:         sigprocmask(SIG_UNBLOCK, $sigset)
  473:             or die "Can't unblock SIGINT for fork: $!\n";
  474:         $children{$pid} = 1;
  475:         $children++;
  476:         &status('Started child '.$pid);
  477:         return;
  478:     } else {
  479:         # Child can *not* return from this subroutine.
  480:         $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
  481:         $SIG{USR1}= \&logstatus;
  482:         $SIG{ALRM}= \&timeout;
  483:         $lastlog='Forked ';
  484:         $status='Forked';
  485: 
  486:         # unblock signals
  487:         sigprocmask(SIG_UNBLOCK, $sigset)
  488:             or die "Can't unblock SIGINT for fork: $!\n";
  489: 
  490:         $tmpsnum=0;
  491:     
  492:         # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
  493:         for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
  494:             &status('Idle, waiting for connection');
  495:             $client = $server->accept()     or last;
  496:             &status('Accepted connection');
  497: # =============================================================================
  498:             # do something with the connection
  499: # -----------------------------------------------------------------------------
  500:             # see if we know client and check for spoof IP by challenge
  501:             my $caller=getpeername($client);
  502:             my ($port,$iaddr)=unpack_sockaddr_in($caller);
  503:             my $clientip=inet_ntoa($iaddr);
  504:             my $clientrec=($hostid{$clientip} ne undef);
  505:             &logthis(
  506: "<font color=yellow>INFO: Connection $i, $clientip ($hostid{$clientip})</font>"
  507:             );
  508:             &status("Connecting $clientip ($hostid{$clientip})"); 
  509:             my $clientok;
  510:             if ($clientrec) {
  511: 	      &status("Waiting for init from $clientip ($hostid{$clientip})");
  512: 	      my $remotereq=<$client>;
  513:               $remotereq=~s/\W//g;
  514:               if ($remotereq eq 'init') {
  515: 		  my $challenge="$$".time;
  516:                   print $client "$challenge\n";
  517:                   &status(
  518:            "Waiting for challenge reply from $clientip ($hostid{$clientip})"); 
  519:                   $remotereq=<$client>;
  520:                   $remotereq=~s/\W//g;
  521:                   if ($challenge eq $remotereq) {
  522: 		      $clientok=1;
  523:                       print $client "ok\n";
  524:                   } else {
  525: 		      &logthis(
  526:  "<font color=blue>WARNING: $clientip did not reply challenge</font>");
  527:                       &status('No challenge reply '.$clientip);
  528:                   }
  529:               } else {
  530: 		  &logthis(
  531:                     "<font color=blue>WARNING: "
  532:                    ."$clientip failed to initialize: >$remotereq< </font>");
  533:                   &status('No init '.$clientip);
  534:               }
  535: 	    } else {
  536:               &logthis(
  537:  "<font color=blue>WARNING: Unknown client $clientip</font>");
  538:               &status('Hung up on '.$clientip);
  539:             }
  540:             if ($clientok) {
  541: # ---------------- New known client connecting, could mean machine online again
  542: 
  543: 	      &reconlonc("$perlvar{'lonSockDir'}/$hostid{$clientip}");
  544:               &logthis(
  545:        "<font color=green>Established connection: $hostid{$clientip}</font>");
  546:               &status('Will listen to '.$hostid{$clientip});
  547: # ------------------------------------------------------------ Process requests
  548:               while (my $userinput=<$client>) {
  549:                 chomp($userinput);
  550: 		Debug("Request = $userinput\n");
  551:                 &status('Processing '.$hostid{$clientip}.': '.$userinput);
  552:                 my $wasenc=0;
  553:                 alarm(120);
  554: # ------------------------------------------------------------ See if encrypted
  555: 		if ($userinput =~ /^enc/) {
  556: 		  if ($cipher) {
  557:                     my ($cmd,$cmdlength,$encinput)=split(/:/,$userinput);
  558: 		    $userinput='';
  559:                     for (my $encidx=0;$encidx<length($encinput);$encidx+=16) {
  560:                        $userinput.=
  561: 			   $cipher->decrypt(
  562:                             pack("H16",substr($encinput,$encidx,16))
  563:                            );
  564: 		    }
  565: 		    $userinput=substr($userinput,0,$cmdlength);
  566:                     $wasenc=1;
  567: 		}
  568: 	      }
  569: 	  
  570: # ------------------------------------------------------------- Normal commands
  571: # ------------------------------------------------------------------------ ping
  572: 		   if ($userinput =~ /^ping/) {
  573:                        print $client "$perlvar{'lonHostID'}\n";
  574: # ------------------------------------------------------------------------ pong
  575: 		   } elsif ($userinput =~ /^pong/) {
  576:                        $reply=reply("ping",$hostid{$clientip});
  577:                        print $client "$perlvar{'lonHostID'}:$reply\n"; 
  578: # ------------------------------------------------------------------------ ekey
  579: 		   } elsif ($userinput =~ /^ekey/) {
  580:                        my $buildkey=time.$$.int(rand 100000);
  581:                        $buildkey=~tr/1-6/A-F/;
  582:                        $buildkey=int(rand 100000).$buildkey.int(rand 100000);
  583:                        my $key=$perlvar{'lonHostID'}.$hostid{$clientip};
  584:                        $key=~tr/a-z/A-Z/;
  585:                        $key=~tr/G-P/0-9/;
  586:                        $key=~tr/Q-Z/0-9/;
  587:                        $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
  588:                        $key=substr($key,0,32);
  589:                        my $cipherkey=pack("H32",$key);
  590:                        $cipher=new IDEA $cipherkey;
  591:                        print $client "$buildkey\n"; 
  592: # ------------------------------------------------------------------------ load
  593: 		   } elsif ($userinput =~ /^load/) {
  594:                        my $loadavg;
  595:                        {
  596:                           my $loadfile=IO::File->new('/proc/loadavg');
  597:                           $loadavg=<$loadfile>;
  598:                        }
  599:                        $loadavg =~ s/\s.*//g;
  600:                        my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};
  601: 		       print $client "$loadpercent\n";
  602: # ----------------------------------------------------------------- currentauth
  603: 		   } elsif ($userinput =~ /^currentauth/) {
  604: 		     if ($wasenc==1) {
  605:                        my ($cmd,$udom,$uname)=split(/:/,$userinput);
  606: 		       my $result = GetAuthType($udom, $uname);
  607: 		       if($result eq "nouser") {
  608: 			   print $client "unknown_user\n";
  609: 		       }
  610: 		       else {
  611: 			   print $client "$result\n"
  612: 		       }
  613: 		     } else {
  614: 		       print $client "refused\n";
  615: 		     }
  616: # ------------------------------------------------------------------------ auth
  617:                    } elsif ($userinput =~ /^auth/) {
  618: 		     if ($wasenc==1) {
  619:                        my ($cmd,$udom,$uname,$upass)=split(/:/,$userinput);
  620:                        chomp($upass);
  621:                        $upass=unescape($upass);
  622:                        my $proname=propath($udom,$uname);
  623:                        my $passfilename="$proname/passwd";
  624:                        if (-e $passfilename) {
  625:                           my $pf = IO::File->new($passfilename);
  626:                           my $realpasswd=<$pf>;
  627:                           chomp($realpasswd);
  628:                           my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
  629:                           my $pwdcorrect=0;
  630:                           if ($howpwd eq 'internal') {
  631: 			      $pwdcorrect=
  632: 				  (crypt($upass,$contentpwd) eq $contentpwd);
  633:                           } elsif ($howpwd eq 'unix') {
  634:                               $contentpwd=(getpwnam($uname))[1];
  635: 			      my $pwauth_path="/usr/local/sbin/pwauth";
  636: 			      unless ($contentpwd eq 'x') {
  637: 				  $pwdcorrect=
  638:                                     (crypt($upass,$contentpwd) eq $contentpwd);
  639: 			      }
  640: 			      elsif (-e $pwauth_path) {
  641: 				  open PWAUTH, "|$pwauth_path" or
  642: 				      die "Cannot invoke authentication";
  643: 				  print PWAUTH "$uname\n$upass\n";
  644: 				  close PWAUTH;
  645: 				  $pwdcorrect=!$?;
  646: 			      }
  647:                           } elsif ($howpwd eq 'krb4') {
  648:                              $null=pack("C",0);
  649: 			     unless ($upass=~/$null/) {
  650:                               $pwdcorrect=(
  651:                                  Authen::Krb4::get_pw_in_tkt($uname,"",
  652:                                         $contentpwd,'krbtgt',$contentpwd,1,
  653: 							     $upass) == 0);
  654: 			     } else { $pwdcorrect=0; }
  655:                           } elsif ($howpwd eq 'localauth') {
  656: 			    $pwdcorrect=&localauth::localauth($uname,$upass,
  657: 							      $contentpwd);
  658: 			  }
  659:                           if ($pwdcorrect) {
  660:                              print $client "authorized\n";
  661:                           } else {
  662:                              print $client "non_authorized\n";
  663:                           }  
  664: 		       } else {
  665:                           print $client "unknown_user\n";
  666:                        }
  667: 		     } else {
  668: 		       print $client "refused\n";
  669: 		     }
  670: # ---------------------------------------------------------------------- passwd
  671:                    } elsif ($userinput =~ /^passwd/) {
  672: 		     if ($wasenc==1) {
  673:                        my 
  674:                        ($cmd,$udom,$uname,$upass,$npass)=split(/:/,$userinput);
  675:                        chomp($npass);
  676:                        $upass=&unescape($upass);
  677:                        $npass=&unescape($npass);
  678: 		       &logthis("Trying to change password for $uname");
  679: 		       my $proname=propath($udom,$uname);
  680:                        my $passfilename="$proname/passwd";
  681:                        if (-e $passfilename) {
  682: 			   my $realpasswd;
  683:                           { my $pf = IO::File->new($passfilename);
  684: 			    $realpasswd=<$pf>; }
  685:                           chomp($realpasswd);
  686:                           my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
  687:                           if ($howpwd eq 'internal') {
  688: 			   if (crypt($upass,$contentpwd) eq $contentpwd) {
  689: 			     my $salt=time;
  690:                              $salt=substr($salt,6,2);
  691: 			     my $ncpass=crypt($npass,$salt);
  692:                              { my $pf = IO::File->new(">$passfilename");
  693:  	  		       print $pf "internal:$ncpass\n"; }             
  694: 			     &logthis("Result of password change for $uname: pwchange_success");
  695:                              print $client "ok\n";
  696:                            } else {
  697:                              print $client "non_authorized\n";
  698:                            }
  699:                           } elsif ($howpwd eq 'unix') {
  700: 			      # Unix means we have to access /etc/password
  701: 			      # one way or another.
  702: 			      # First: Make sure the current password is
  703: 			      #        correct
  704: 			      $contentpwd=(getpwnam($uname))[1];
  705: 			      my $pwdcorrect = "0";
  706: 			      my $pwauth_path="/usr/local/sbin/pwauth";
  707: 			      unless ($contentpwd eq 'x') {
  708: 				  $pwdcorrect=
  709:                                     (crypt($upass,$contentpwd) eq $contentpwd);
  710: 			      } elsif (-e $pwauth_path) {
  711: 				  open PWAUTH, "|$pwauth_path" or
  712: 				      die "Cannot invoke authentication";
  713: 				  print PWAUTH "$uname\n$upass\n";
  714: 				  close PWAUTH;
  715: 				  $pwdcorrect=!$?;
  716: 			      }
  717: 			     if ($pwdcorrect) {
  718: 				 my $execdir=$perlvar{'lonDaemons'};
  719: 				 my $pf = IO::File->new("|$execdir/lcpasswd");
  720: 				 print $pf "$uname\n$npass\n$npass\n";
  721: 				 close $pf;
  722: 				 my $result = ($?>0 ? 'pwchange_failure' 
  723: 					       : 'ok');
  724: 				 &logthis("Result of password change for $uname: $result");
  725: 				 print $client "$result\n";
  726: 			     } else {
  727: 				 print $client "non_authorized\n";
  728: 			     }
  729: 			  } else {
  730:                             print $client "auth_mode_error\n";
  731:                           }  
  732: 		       } else {
  733:                           print $client "unknown_user\n";
  734:                        }
  735: 		     } else {
  736: 		       print $client "refused\n";
  737: 		     }
  738: # -------------------------------------------------------------------- makeuser
  739:                    } elsif ($userinput =~ /^makeuser/) {
  740: 		     Debug("Make user received");
  741:     	             my $oldumask=umask(0077);
  742: 		     if ($wasenc==1) {
  743:                        my 
  744:                        ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
  745: 		       &Debug("cmd =".$cmd." $udom =".$udom.
  746: 				    " uname=".$uname);
  747:                        chomp($npass);
  748:                        $npass=&unescape($npass);
  749:                        my $proname=propath($udom,$uname);
  750:                        my $passfilename="$proname/passwd";
  751: 		       &Debug("Password file created will be:".
  752: 				    $passfilename);
  753:                        if (-e $passfilename) {
  754: 			   print $client "already_exists\n";
  755:                        } elsif ($udom ne $perlvar{'lonDefDomain'}) {
  756:                            print $client "not_right_domain\n";
  757:                        } else {
  758:                            @fpparts=split(/\//,$proname);
  759:                            $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];
  760:                            $fperror='';
  761:                            for ($i=3;$i<=$#fpparts;$i++) {
  762:                                $fpnow.='/'.$fpparts[$i]; 
  763:                                unless (-e $fpnow) {
  764: 				   unless (mkdir($fpnow,0777)) {
  765:                                       $fperror="error:$!";
  766:                                    }
  767:                                }
  768:                            }
  769:                            unless ($fperror) {
  770: 			     if ($umode eq 'krb4') {
  771:                                { 
  772:                                  my $pf = IO::File->new(">$passfilename");
  773:  	  		         print $pf "krb4:$npass\n"; 
  774:                                }             
  775:                                print $client "ok\n";
  776:                              } elsif ($umode eq 'internal') {
  777: 			       my $salt=time;
  778:                                $salt=substr($salt,6,2);
  779: 			       my $ncpass=crypt($npass,$salt);
  780:                                { 
  781: 				 &Debug("Creating internal auth");
  782: 				 my $pf = IO::File->new(">$passfilename");
  783:  	  		         print $pf "internal:$ncpass\n"; 
  784:                                }
  785:                                print $client "ok\n";
  786: 			     } elsif ($umode eq 'localauth') {
  787: 			       {
  788: 				 my $pf = IO::File->new(">$passfilename");
  789:   	  		         print $pf "localauth:$npass\n";
  790: 			       }
  791: 			       print $client "ok\n";
  792: 			     } elsif ($umode eq 'unix') {
  793: 			       {
  794: 				 my $execpath="$perlvar{'lonDaemons'}/".
  795: 				              "lcuseradd";
  796: 				 {
  797: 				     &Debug("Executing external: ".
  798: 						  $execpath);
  799: 				     my $se = IO::File->new("|$execpath");
  800: 				     print $se "$uname\n";
  801: 				     print $se "$npass\n";
  802: 				     print $se "$npass\n";
  803: 				 }
  804:                                  my $pf = IO::File->new(">$passfilename");
  805:  	  		         print $pf "unix:\n"; 
  806: 			       }
  807: 			       print $client "ok\n";
  808: 			     } elsif ($umode eq 'none') {
  809:                                { 
  810:                                  my $pf = IO::File->new(">$passfilename");
  811:  	  		         print $pf "none:\n"; 
  812:                                }             
  813:                                print $client "ok\n";
  814:                              } else {
  815:                                print $client "auth_mode_error\n";
  816:                              }  
  817:                            } else {
  818:                                print $client "$fperror\n";
  819:                            }
  820:                        }
  821: 		     } else {
  822: 		       print $client "refused\n";
  823: 		     }
  824: 		     umask($oldumask);
  825: # -------------------------------------------------------------- changeuserauth
  826:                    } elsif ($userinput =~ /^changeuserauth/) {
  827: 		       &Debug("Changing authorization");
  828: 		      if ($wasenc==1) {
  829:                        my 
  830:                        ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
  831:                        chomp($npass);
  832: 		       &Debug("cmd = ".$cmd." domain= ".$udom.
  833: 			      "uname =".$uname." umode= ".$umode);
  834:                        $npass=&unescape($npass);
  835:                        my $proname=propath($udom,$uname);
  836:                        my $passfilename="$proname/passwd";
  837: 		       if ($udom ne $perlvar{'lonDefDomain'}) {
  838:                            print $client "not_right_domain\n";
  839:                        } else {
  840: 			   if ($umode eq 'krb4') {
  841:                                { 
  842: 				   my $pf = IO::File->new(">$passfilename");
  843: 				   print $pf "krb4:$npass\n"; 
  844:                                }             
  845:                                print $client "ok\n";
  846: 			   } elsif ($umode eq 'internal') {
  847: 			       my $salt=time;
  848:                                $salt=substr($salt,6,2);
  849: 			       my $ncpass=crypt($npass,$salt);
  850:                                { 
  851: 				   my $pf = IO::File->new(">$passfilename");
  852: 				   print $pf "internal:$ncpass\n"; 
  853:                                }
  854:                                print $client "ok\n";
  855: 			   } elsif ($umode eq 'localauth') {
  856: 			       {
  857: 				   my $pf = IO::File->new(">$passfilename");
  858: 				   print $pf "localauth:$npass\n";
  859: 			       }
  860: 			       print $client "ok\n";
  861: 			   } elsif ($umode eq 'unix') {
  862: 			       {
  863: 				   my $execpath="$perlvar{'lonDaemons'}/".
  864: 				       "lcuseradd";
  865: 				   {
  866: 				       my $se = IO::File->new("|$execpath");
  867: 				       print $se "$uname\n";
  868: 				       print $se "$npass\n";
  869: 				       print $se "$npass\n";
  870: 				   }
  871: 				   my $pf = IO::File->new(">$passfilename");
  872: 				   print $pf "unix:\n"; 
  873: 			       }
  874: 			       print $client "ok\n";
  875: 			   } elsif ($umode eq 'none') {
  876:                                { 
  877: 				   my $pf = IO::File->new(">$passfilename");
  878: 				   print $pf "none:\n"; 
  879:                                }             
  880:                                print $client "ok\n";
  881: 			   } else {
  882:                                print $client "auth_mode_error\n";
  883: 			   }  
  884:                        }
  885: 		     } else {
  886: 		       print $client "refused\n";
  887: 		     }
  888: # ------------------------------------------------------------------------ home
  889:                    } elsif ($userinput =~ /^home/) {
  890:                        my ($cmd,$udom,$uname)=split(/:/,$userinput);
  891:                        chomp($uname);
  892:                        my $proname=propath($udom,$uname);
  893:                        if (-e $proname) {
  894:                           print $client "found\n";
  895:                        } else {
  896: 			  print $client "not_found\n";
  897:                        }
  898: # ---------------------------------------------------------------------- update
  899:                    } elsif ($userinput =~ /^update/) {
  900:                        my ($cmd,$fname)=split(/:/,$userinput);
  901:                        my $ownership=ishome($fname);
  902:                        if ($ownership eq 'not_owner') {
  903:                         if (-e $fname) {
  904:                           my ($dev,$ino,$mode,$nlink,
  905:                               $uid,$gid,$rdev,$size,
  906:                               $atime,$mtime,$ctime,
  907:                               $blksize,$blocks)=stat($fname);
  908:                           $now=time;
  909:                           $since=$now-$atime;
  910:                           if ($since>$perlvar{'lonExpire'}) {
  911:                               $reply=
  912:                                     reply("unsub:$fname","$hostid{$clientip}");
  913:                               unlink("$fname");
  914:                           } else {
  915: 			     my $transname="$fname.in.transfer";
  916:                              my $remoteurl=
  917:                                     reply("sub:$fname","$hostid{$clientip}");
  918:                              my $response;
  919:                               {
  920:                              my $ua=new LWP::UserAgent;
  921:                              my $request=new HTTP::Request('GET',"$remoteurl");
  922:                              $response=$ua->request($request,$transname);
  923: 			      }
  924:                              if ($response->is_error()) {
  925: 				 unlink($transname);
  926:                                  my $message=$response->status_line;
  927:                                  &logthis(
  928:                                   "LWP GET: $message for $fname ($remoteurl)");
  929:                              } else {
  930: 	                         if ($remoteurl!~/\.meta$/) {
  931:                                   my $ua=new LWP::UserAgent;
  932:                                   my $mrequest=
  933:                                    new HTTP::Request('GET',$remoteurl.'.meta');
  934:                                   my $mresponse=
  935:                                    $ua->request($mrequest,$fname.'.meta');
  936:                                   if ($mresponse->is_error()) {
  937: 		                    unlink($fname.'.meta');
  938:                                   }
  939: 	                         }
  940:                                  rename($transname,$fname);
  941: 			     }
  942:                           }
  943:                           print $client "ok\n";
  944:                         } else {
  945:                           print $client "not_found\n";
  946:                         }
  947: 		       } else {
  948: 			print $client "rejected\n";
  949:                        }
  950: # ----------------------------------------------------------------- unsubscribe
  951:                    } elsif ($userinput =~ /^unsub/) {
  952:                        my ($cmd,$fname)=split(/:/,$userinput);
  953:                        if (-e $fname) {
  954:                            if (unlink("$fname.$hostid{$clientip}")) {
  955:                               print $client "ok\n";
  956: 			   } else {
  957:                               print $client "not_subscribed\n";
  958: 			   }
  959:                        } else {
  960: 			   print $client "not_found\n";
  961:                        }
  962: # ------------------------------------------------------------------- subscribe
  963:                    } elsif ($userinput =~ /^sub/) {
  964:                        my ($cmd,$fname)=split(/:/,$userinput);
  965:                        my $ownership=ishome($fname);
  966:                        if ($ownership eq 'owner') {
  967:                         if (-e $fname) {
  968: 			 if (-d $fname) {
  969: 			   print $client "directory\n";
  970:                          } else {
  971:                            $now=time;
  972:                            { 
  973: 			    my $sh;
  974:                             if ($sh=
  975:                              IO::File->new(">$fname.$hostid{$clientip}")) {
  976:                                print $sh "$clientip:$now\n";
  977: 			    }
  978: 			   }
  979:                            unless ($fname=~/\.meta$/) {
  980: 			       unlink("$fname.meta.$hostid{$clientip}");
  981:                            }
  982:                            $fname=~s/\/home\/httpd\/html\/res/raw/;
  983:                            $fname="http://$thisserver/".$fname;
  984:                            print $client "$fname\n";
  985: 		         }
  986:                         } else {
  987: 		      	   print $client "not_found\n";
  988:                         }
  989: 		       } else {
  990:                         print $client "rejected\n";
  991: 		       }
  992: # ------------------------------------------------------------------------- log
  993:                    } elsif ($userinput =~ /^log/) {
  994:                        my ($cmd,$udom,$uname,$what)=split(/:/,$userinput);
  995:                        chomp($what);
  996:                        my $proname=propath($udom,$uname);
  997:                        my $now=time;
  998:                        {
  999: 			 my $hfh;
 1000: 			 if ($hfh=IO::File->new(">>$proname/activity.log")) { 
 1001:                             print $hfh "$now:$hostid{$clientip}:$what\n";
 1002:                             print $client "ok\n"; 
 1003: 			} else {
 1004:                             print $client "error:$!\n";
 1005: 		        }
 1006: 		       }
 1007: # ------------------------------------------------------------------------- put
 1008:                    } elsif ($userinput =~ /^put/) {
 1009:                       my ($cmd,$udom,$uname,$namespace,$what)
 1010:                           =split(/:/,$userinput);
 1011:                       $namespace=~s/\//\_/g;
 1012:                       $namespace=~s/\W//g;
 1013:                       if ($namespace ne 'roles') {
 1014:                        chomp($what);
 1015:                        my $proname=propath($udom,$uname);
 1016:                        my $now=time;
 1017:                        unless ($namespace=~/^nohist\_/) {
 1018: 			   my $hfh;
 1019: 			   if (
 1020:                              $hfh=IO::File->new(">>$proname/$namespace.hist")
 1021: 			       ) { print $hfh "P:$now:$what\n"; }
 1022: 		       }
 1023:                        my @pairs=split(/\&/,$what);
 1024:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
 1025:                            foreach $pair (@pairs) {
 1026: 			       ($key,$value)=split(/=/,$pair);
 1027:                                $hash{$key}=$value;
 1028:                            }
 1029: 			   if (untie(%hash)) {
 1030:                               print $client "ok\n";
 1031:                            } else {
 1032:                               print $client "error:$!\n";
 1033:                            }
 1034:                        } else {
 1035:                            print $client "error:$!\n";
 1036:                        }
 1037: 		      } else {
 1038:                           print $client "refused\n";
 1039:                       }
 1040: # -------------------------------------------------------------------- rolesput
 1041:                    } elsif ($userinput =~ /^rolesput/) {
 1042: 		       &Debug("rolesput");
 1043: 		    if ($wasenc==1) {
 1044:                        my ($cmd,$exedom,$exeuser,$udom,$uname,$what)
 1045:                           =split(/:/,$userinput);
 1046: 		       &Debug("cmd = ".$cmd." exedom= ".$exedom.
 1047: 				    "user = ".$exeuser." udom=".$udom.
 1048: 				    "what = ".$what);
 1049:                        my $namespace='roles';
 1050:                        chomp($what);
 1051:                        my $proname=propath($udom,$uname);
 1052:                        my $now=time;
 1053:                        {
 1054: 			   my $hfh;
 1055: 			   if (
 1056:                              $hfh=IO::File->new(">>$proname/$namespace.hist")
 1057: 			       ) { 
 1058:                                   print $hfh "P:$now:$exedom:$exeuser:$what\n";
 1059:                                  }
 1060: 		       }
 1061:                        my @pairs=split(/\&/,$what);
 1062:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
 1063:                            foreach $pair (@pairs) {
 1064: 			       ($key,$value)=split(/=/,$pair);
 1065: 			       &ManagePermissions($key, $udom, $uname,
 1066: 						  &GetAuthType( $udom, 
 1067: 								$uname));
 1068:                                $hash{$key}=$value;
 1069: 			       
 1070:                            }
 1071: 			   if (untie(%hash)) {
 1072:                               print $client "ok\n";
 1073:                            } else {
 1074:                               print $client "error:$!\n";
 1075:                            }
 1076:                        } else {
 1077:                            print $client "error:$!\n";
 1078:                        }
 1079: 		      } else {
 1080:                           print $client "refused\n";
 1081:                       }
 1082: # ------------------------------------------------------------------------- get
 1083:                    } elsif ($userinput =~ /^get/) {
 1084:                        my ($cmd,$udom,$uname,$namespace,$what)
 1085:                           =split(/:/,$userinput);
 1086:                        $namespace=~s/\//\_/g;
 1087:                        $namespace=~s/\W//g;
 1088:                        chomp($what);
 1089:                        my @queries=split(/\&/,$what);
 1090:                        my $proname=propath($udom,$uname);
 1091:                        my $qresult='';
 1092:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
 1093:                            for ($i=0;$i<=$#queries;$i++) {
 1094:                                $qresult.="$hash{$queries[$i]}&";
 1095:                            }
 1096: 			   if (untie(%hash)) {
 1097: 		              $qresult=~s/\&$//;
 1098:                               print $client "$qresult\n";
 1099:                            } else {
 1100:                               print $client "error:$!\n";
 1101:                            }
 1102:                        } else {
 1103:                            print $client "error:$!\n";
 1104:                        }
 1105: # ------------------------------------------------------------------------ eget
 1106:                    } elsif ($userinput =~ /^eget/) {
 1107:                        my ($cmd,$udom,$uname,$namespace,$what)
 1108:                           =split(/:/,$userinput);
 1109:                        $namespace=~s/\//\_/g;
 1110:                        $namespace=~s/\W//g;
 1111:                        chomp($what);
 1112:                        my @queries=split(/\&/,$what);
 1113:                        my $proname=propath($udom,$uname);
 1114:                        my $qresult='';
 1115:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
 1116:                            for ($i=0;$i<=$#queries;$i++) {
 1117:                                $qresult.="$hash{$queries[$i]}&";
 1118:                            }
 1119: 			   if (untie(%hash)) {
 1120: 		              $qresult=~s/\&$//;
 1121:                               if ($cipher) {
 1122:                                 my $cmdlength=length($qresult);
 1123:                                 $qresult.="         ";
 1124:                                 my $encqresult='';
 1125:                                 for 
 1126: 				(my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
 1127:                                  $encqresult.=
 1128:                                  unpack("H16",
 1129:                                  $cipher->encrypt(substr($qresult,$encidx,8)));
 1130:                                 }
 1131:                                 print $client "enc:$cmdlength:$encqresult\n";
 1132: 			      } else {
 1133: 			        print $client "error:no_key\n";
 1134:                               }
 1135:                            } else {
 1136:                               print $client "error:$!\n";
 1137:                            }
 1138:                        } else {
 1139:                            print $client "error:$!\n";
 1140:                        }
 1141: # ------------------------------------------------------------------------- del
 1142:                    } elsif ($userinput =~ /^del/) {
 1143:                        my ($cmd,$udom,$uname,$namespace,$what)
 1144:                           =split(/:/,$userinput);
 1145:                        $namespace=~s/\//\_/g;
 1146:                        $namespace=~s/\W//g;
 1147:                        chomp($what);
 1148:                        my $proname=propath($udom,$uname);
 1149:                        my $now=time;
 1150:                        unless ($namespace=~/^nohist\_/) {
 1151: 			   my $hfh;
 1152: 			   if (
 1153:                              $hfh=IO::File->new(">>$proname/$namespace.hist")
 1154: 			       ) { print $hfh "D:$now:$what\n"; }
 1155: 		       }
 1156:                        my @keys=split(/\&/,$what);
 1157:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
 1158:                            foreach $key (@keys) {
 1159:                                delete($hash{$key});
 1160:                            }
 1161: 			   if (untie(%hash)) {
 1162:                               print $client "ok\n";
 1163:                            } else {
 1164:                               print $client "error:$!\n";
 1165:                            }
 1166:                        } else {
 1167:                            print $client "error:$!\n";
 1168:                        }
 1169: # ------------------------------------------------------------------------ keys
 1170:                    } elsif ($userinput =~ /^keys/) {
 1171:                        my ($cmd,$udom,$uname,$namespace)
 1172:                           =split(/:/,$userinput);
 1173:                        $namespace=~s/\//\_/g;
 1174:                        $namespace=~s/\W//g;
 1175:                        my $proname=propath($udom,$uname);
 1176:                        my $qresult='';
 1177:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
 1178:                            foreach $key (keys %hash) {
 1179:                                $qresult.="$key&";
 1180:                            }
 1181: 			   if (untie(%hash)) {
 1182: 		              $qresult=~s/\&$//;
 1183:                               print $client "$qresult\n";
 1184:                            } else {
 1185:                               print $client "error:$!\n";
 1186:                            }
 1187:                        } else {
 1188:                            print $client "error:$!\n";
 1189:                        }
 1190: # ------------------------------------------------------------------------ dump
 1191:                    } elsif ($userinput =~ /^dump/) {
 1192:                        my ($cmd,$udom,$uname,$namespace,$regexp)
 1193:                           =split(/:/,$userinput);
 1194:                        $namespace=~s/\//\_/g;
 1195:                        $namespace=~s/\W//g;
 1196:                        if (defined($regexp)) {
 1197:                           $regexp=&unescape($regexp);
 1198: 		       } else {
 1199:                           $regexp='.';
 1200: 		       }
 1201:                        my $proname=propath($udom,$uname);
 1202:                        my $qresult='';
 1203:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
 1204:                            foreach $key (keys %hash) {
 1205:                                if (eval('$key=~/$regexp/')) {
 1206:                                   $qresult.="$key=$hash{$key}&";
 1207: 			       }
 1208:                            }
 1209: 			   if (untie(%hash)) {
 1210: 		              $qresult=~s/\&$//;
 1211:                               print $client "$qresult\n";
 1212:                            } else {
 1213:                               print $client "error:$!\n";
 1214:                            }
 1215:                        } else {
 1216:                            print $client "error:$!\n";
 1217:                        }
 1218: # ----------------------------------------------------------------------- store
 1219:                    } elsif ($userinput =~ /^store/) {
 1220:                       my ($cmd,$udom,$uname,$namespace,$rid,$what)
 1221:                           =split(/:/,$userinput);
 1222:                       $namespace=~s/\//\_/g;
 1223:                       $namespace=~s/\W//g;
 1224:                       if ($namespace ne 'roles') {
 1225:                        chomp($what);
 1226:                        my $proname=propath($udom,$uname);
 1227:                        my $now=time;
 1228:                        unless ($namespace=~/^nohist\_/) {
 1229: 			   my $hfh;
 1230: 			   if (
 1231:                              $hfh=IO::File->new(">>$proname/$namespace.hist")
 1232: 			       ) { print $hfh "P:$now:$rid:$what\n"; }
 1233: 		       }
 1234:                        my @pairs=split(/\&/,$what);
 1235:                          
 1236:     if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
 1237:                            my @previouskeys=split(/&/,$hash{"keys:$rid"});
 1238:                            my $key;
 1239:                            $hash{"version:$rid"}++;
 1240:                            my $version=$hash{"version:$rid"};
 1241:                            my $allkeys=''; 
 1242:                            foreach $pair (@pairs) {
 1243: 			       ($key,$value)=split(/=/,$pair);
 1244:                                $allkeys.=$key.':';
 1245:                                $hash{"$version:$rid:$key"}=$value;
 1246:                            }
 1247:                            $hash{"$version:$rid:timestamp"}=$now;
 1248:                            $allkeys.='timestamp';
 1249:                            $hash{"$version:keys:$rid"}=$allkeys;
 1250: 			   if (untie(%hash)) {
 1251:                               print $client "ok\n";
 1252:                            } else {
 1253:                               print $client "error:$!\n";
 1254:                            }
 1255:                        } else {
 1256:                            print $client "error:$!\n";
 1257:                        }
 1258: 		      } else {
 1259:                           print $client "refused\n";
 1260:                       }
 1261: # --------------------------------------------------------------------- restore
 1262:                    } elsif ($userinput =~ /^restore/) {
 1263:                        my ($cmd,$udom,$uname,$namespace,$rid)
 1264:                           =split(/:/,$userinput);
 1265:                        $namespace=~s/\//\_/g;
 1266:                        $namespace=~s/\W//g;
 1267:                        chomp($rid);
 1268:                        my $proname=propath($udom,$uname);
 1269:                        my $qresult='';
 1270:       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
 1271:                 	   my $version=$hash{"version:$rid"};
 1272:                            $qresult.="version=$version&";
 1273:                            my $scope;
 1274:                            for ($scope=1;$scope<=$version;$scope++) {
 1275: 			      my $vkeys=$hash{"$scope:keys:$rid"};
 1276:                               my @keys=split(/:/,$vkeys);
 1277:                               my $key;
 1278:                               $qresult.="$scope:keys=$vkeys&";
 1279:                               foreach $key (@keys) {
 1280: 	     $qresult.="$scope:$key=".$hash{"$scope:$rid:$key"}."&";
 1281:                               }                                  
 1282:                            }
 1283: 			   if (untie(%hash)) {
 1284: 		              $qresult=~s/\&$//;
 1285:                               print $client "$qresult\n";
 1286:                            } else {
 1287:                               print $client "error:$!\n";
 1288:                            }
 1289:                        } else {
 1290:                            print $client "error:$!\n";
 1291:                        }
 1292: # ------------------------------------------------------------------- querysend
 1293:                    } elsif ($userinput =~ /^querysend/) {
 1294:                        my ($cmd,$query,
 1295: 			   $custom,$customshow)=split(/:/,$userinput);
 1296: 		       $query=~s/\n*$//g;
 1297: 		       unless ($custom or $customshow) {
 1298: 			   print $client "".
 1299: 			       sqlreply("$hostid{$clientip}\&$query")."\n";
 1300: 		       }
 1301: 		       else {
 1302: 			   print $client "".
 1303: 			       sqlreply("$hostid{$clientip}\&$query".
 1304: 					"\&$custom"."\&$customshow")."\n";
 1305: 		       }
 1306: # ------------------------------------------------------------------ queryreply
 1307:                    } elsif ($userinput =~ /^queryreply/) {
 1308:                        my ($cmd,$id,$reply)=split(/:/,$userinput); 
 1309: 		       my $store;
 1310:                        my $execdir=$perlvar{'lonDaemons'};
 1311:                        if ($store=IO::File->new(">$execdir/tmp/$id")) {
 1312: 			   $reply=~s/\&/\n/g;
 1313: 			   print $store $reply;
 1314: 			   close $store;
 1315: 			   my $store2=IO::File->new(">$execdir/tmp/$id.end");
 1316: 			   print $store2 "done\n";
 1317: 			   close $store2;
 1318: 			   print $client "ok\n";
 1319: 		       }
 1320: 		       else {
 1321: 			   print $client "error:$!\n";
 1322: 		       }
 1323: # ----------------------------------------------------------------------- idput
 1324:                    } elsif ($userinput =~ /^idput/) {
 1325:                        my ($cmd,$udom,$what)=split(/:/,$userinput);
 1326:                        chomp($what);
 1327:                        $udom=~s/\W//g;
 1328:                        my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
 1329:                        my $now=time;
 1330:                        {
 1331: 			   my $hfh;
 1332: 			   if (
 1333:                              $hfh=IO::File->new(">>$proname.hist")
 1334: 			       ) { print $hfh "P:$now:$what\n"; }
 1335: 		       }
 1336:                        my @pairs=split(/\&/,$what);
 1337:                  if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT,0640)) {
 1338:                            foreach $pair (@pairs) {
 1339: 			       ($key,$value)=split(/=/,$pair);
 1340:                                $hash{$key}=$value;
 1341:                            }
 1342: 			   if (untie(%hash)) {
 1343:                               print $client "ok\n";
 1344:                            } else {
 1345:                               print $client "error:$!\n";
 1346:                            }
 1347:                        } else {
 1348:                            print $client "error:$!\n";
 1349:                        }
 1350: # ----------------------------------------------------------------------- idget
 1351:                    } elsif ($userinput =~ /^idget/) {
 1352:                        my ($cmd,$udom,$what)=split(/:/,$userinput);
 1353:                        chomp($what);
 1354:                        $udom=~s/\W//g;
 1355:                        my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
 1356:                        my @queries=split(/\&/,$what);
 1357:                        my $qresult='';
 1358:                  if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER,0640)) {
 1359:                            for ($i=0;$i<=$#queries;$i++) {
 1360:                                $qresult.="$hash{$queries[$i]}&";
 1361:                            }
 1362: 			   if (untie(%hash)) {
 1363: 		              $qresult=~s/\&$//;
 1364:                               print $client "$qresult\n";
 1365:                            } else {
 1366:                               print $client "error:$!\n";
 1367:                            }
 1368:                        } else {
 1369:                            print $client "error:$!\n";
 1370:                        }
 1371: # ---------------------------------------------------------------------- tmpput
 1372:                    } elsif ($userinput =~ /^tmpput/) {
 1373:                        my ($cmd,$what)=split(/:/,$userinput);
 1374: 		       my $store;
 1375:                        $tmpsnum++;
 1376:                        my $id=$$.'_'.$clientip.'_'.$tmpsnum;
 1377:                        $id=~s/\W/\_/g;
 1378:                        $what=~s/\n//g;
 1379:                        my $execdir=$perlvar{'lonDaemons'};
 1380:                        if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {
 1381: 			   print $store $what;
 1382: 			   close $store;
 1383: 			   print $client "$id\n";
 1384: 		       }
 1385: 		       else {
 1386: 			   print $client "error:$!\n";
 1387: 		       }
 1388: 
 1389: # ---------------------------------------------------------------------- tmpget
 1390:                    } elsif ($userinput =~ /^tmpget/) {
 1391:                        my ($cmd,$id)=split(/:/,$userinput);
 1392:                        chomp($id);
 1393:                        $id=~s/\W/\_/g;
 1394:                        my $store;
 1395:                        my $execdir=$perlvar{'lonDaemons'};
 1396:                        if ($store=IO::File->new("$execdir/tmp/$id.tmp")) {
 1397:                            my $reply=<$store>;
 1398: 			   print $client "$reply\n";
 1399:                            close $store;
 1400: 		       }
 1401: 		       else {
 1402: 			   print $client "error:$!\n";
 1403: 		       }
 1404: 
 1405: # -------------------------------------------------------------------------- ls
 1406:                    } elsif ($userinput =~ /^ls/) {
 1407:                        my ($cmd,$ulsdir)=split(/:/,$userinput);
 1408:                        my $ulsout='';
 1409:                        my $ulsfn;
 1410:                        if (-e $ulsdir) {
 1411: 			if (opendir(LSDIR,$ulsdir)) {
 1412:                           while ($ulsfn=readdir(LSDIR)) {
 1413: 			     my @ulsstats=stat($ulsdir.'/'.$ulsfn);
 1414:                              $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
 1415:                           }
 1416:                           closedir(LSDIR);
 1417: 		        }
 1418: 		       } else {
 1419:                           $ulsout='no_such_dir';
 1420:                        }
 1421:                        if ($ulsout eq '') { $ulsout='empty'; }
 1422:                        print $client "$ulsout\n";
 1423: # ------------------------------------------------------------------ Hanging up
 1424:                    } elsif (($userinput =~ /^exit/) ||
 1425:                             ($userinput =~ /^init/)) {
 1426:                        &logthis(
 1427:       "Client $clientip ($hostid{$clientip}) hanging up: $userinput");
 1428:                        print $client "bye\n";
 1429:                        $client->close();
 1430: 		       last;
 1431: # ------------------------------------------------------------- unknown command
 1432:                    } else {
 1433:                        # unknown command
 1434:                        print $client "unknown_cmd\n";
 1435:                    }
 1436: # -------------------------------------------------------------------- complete
 1437: 		   alarm(0);
 1438:                    &status('Listening to '.$hostid{$clientip});
 1439: 	       }
 1440: # --------------------------------------------- client unknown or fishy, refuse
 1441:             } else {
 1442: 	        print $client "refused\n";
 1443:                 $client->close();
 1444:                 &logthis("<font color=blue>WARNING: "
 1445:                 ."Rejected client $clientip, closing connection</font>");
 1446:             }
 1447: 	}              
 1448: 
 1449: # =============================================================================
 1450:        
 1451: 	&logthis("<font color=red>CRITICAL: "
 1452: 		 ."Disconnect from $clientip ($hostid{$clientip})</font>");    
 1453:         # tidy up gracefully and finish
 1454:     
 1455:         $server->close();
 1456: 
 1457:         # this exit is VERY important, otherwise the child will become
 1458:         # a producer of more and more children, forking yourself into
 1459:         # process death.
 1460:         exit;
 1461:     }
 1462: }
 1463: 
 1464: 
 1465: #
 1466: #   Checks to see if the input roleput request was to set
 1467: # an author role.  If so, invokes the lchtmldir script to set
 1468: # up a correct public_html 
 1469: # Parameters:
 1470: #    request   - The request sent to the rolesput subchunk.
 1471: #                We're looking for  /domain/_au
 1472: #    domain    - The domain in which the user is having roles doctored.
 1473: #    user      - Name of the user for which the role is being put.
 1474: #    authtype  - The authentication type associated with the user.
 1475: #
 1476: sub ManagePermissions
 1477: {
 1478:     my $request = shift;
 1479:     my $domain  = shift;
 1480:     my $user    = shift;
 1481:     my $authtype= shift;
 1482: 
 1483:     # See if the request is of the form /$domain/_au
 1484: 
 1485:     if($request =~ /^(\/$domain\/_au)$/) { # It's an author rolesput...
 1486: 	my $execdir = $perlvar{'lonDaemons'};
 1487: 	my $userhome= "/home/$user" ;
 1488: 	Debug("system $execdir/lchtmldir $userhome $system $authtype");
 1489: 	system("$execdir/lchtmldir $userhome $user $authtype");
 1490:     }
 1491: }
 1492: #
 1493: #   GetAuthType - Determines the authorization type of a user in a domain.
 1494: 
 1495: #     Returns the authorization type or nouser if there is no such user.
 1496: #
 1497: sub GetAuthType 
 1498: {
 1499:     my $domain = shift;
 1500:     my $user   = shift;
 1501: 
 1502:     Debug("GetAuthType( $domain, $user ) \n");
 1503:     my $proname    = &propath($domain, $user); 
 1504:     my $passwdfile = "$proname/passwd";
 1505:     if( -e $passwdfile ) {
 1506: 	my $pf = IO::File->new($passwdfile);
 1507: 	my $realpassword = <$pf>;
 1508: 	chomp($realpassword);
 1509: 	Debug("Password info = $realpassword\n");
 1510: 	my ($authtype, $contentpwd) = split(/:/, $realpassword);
 1511: 	Debug("Authtype = $authtype, content = $contentpwd\n");
 1512: 	my $availinfo = '';
 1513: 	if($authtype eq 'krb4') {
 1514: 	    $availinfo = $contentpwd;
 1515: 	}
 1516: 
 1517: 	return "$authtype:$availinfo";
 1518:     }
 1519:     else {
 1520: 	Debug("Returning nouser");
 1521: 	return "nouser";
 1522:     }
 1523:     
 1524: }
 1525: 
 1526: # ----------------------------------- POD (plain old documentation, CPAN style)
 1527: 
 1528: =head1 NAME
 1529: 
 1530: lond - "LON Daemon" Server (port "LOND" 5663)
 1531: 
 1532: =head1 SYNOPSIS
 1533: 
 1534: Usage: B<lond>
 1535: 
 1536: Should only be run as user=www.  This is a command-line script which
 1537: is invoked by B<loncron>.  There is no expectation that a typical user
 1538: will manually start B<lond> from the command-line.  (In other words,
 1539: DO NOT START B<lond> YOURSELF.)
 1540: 
 1541: =head1 DESCRIPTION
 1542: 
 1543: There are two characteristics associated with the running of B<lond>,
 1544: PROCESS MANAGEMENT (starting, stopping, handling child processes)
 1545: and SERVER-SIDE ACTIVITIES (password authentication, user creation,
 1546: subscriptions, etc).  These are described in two large
 1547: sections below.
 1548: 
 1549: B<PROCESS MANAGEMENT>
 1550: 
 1551: Preforker - server who forks first. Runs as a daemon. HUPs.
 1552: Uses IDEA encryption
 1553: 
 1554: B<lond> forks off children processes that correspond to the other servers
 1555: in the network.  Management of these processes can be done at the
 1556: parent process level or the child process level.
 1557: 
 1558: B<logs/lond.log> is the location of log messages.
 1559: 
 1560: The process management is now explained in terms of linux shell commands,
 1561: subroutines internal to this code, and signal assignments:
 1562: 
 1563: =over 4
 1564: 
 1565: =item *
 1566: 
 1567: PID is stored in B<logs/lond.pid>
 1568: 
 1569: This is the process id number of the parent B<lond> process.
 1570: 
 1571: =item *
 1572: 
 1573: SIGTERM and SIGINT
 1574: 
 1575: Parent signal assignment:
 1576:  $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
 1577: 
 1578: Child signal assignment:
 1579:  $SIG{INT}  = 'DEFAULT'; (and SIGTERM is DEFAULT also)
 1580: (The child dies and a SIGALRM is sent to parent, awaking parent from slumber
 1581:  to restart a new child.)
 1582: 
 1583: Command-line invocations:
 1584:  B<kill> B<-s> SIGTERM I<PID>
 1585:  B<kill> B<-s> SIGINT I<PID>
 1586: 
 1587: Subroutine B<HUNTSMAN>:
 1588:  This is only invoked for the B<lond> parent I<PID>.
 1589: This kills all the children, and then the parent.
 1590: The B<lonc.pid> file is cleared.
 1591: 
 1592: =item *
 1593: 
 1594: SIGHUP
 1595: 
 1596: Current bug:
 1597:  This signal can only be processed the first time
 1598: on the parent process.  Subsequent SIGHUP signals
 1599: have no effect.
 1600: 
 1601: Parent signal assignment:
 1602:  $SIG{HUP}  = \&HUPSMAN;
 1603: 
 1604: Child signal assignment:
 1605:  none (nothing happens)
 1606: 
 1607: Command-line invocations:
 1608:  B<kill> B<-s> SIGHUP I<PID>
 1609: 
 1610: Subroutine B<HUPSMAN>:
 1611:  This is only invoked for the B<lond> parent I<PID>,
 1612: This kills all the children, and then the parent.
 1613: The B<lond.pid> file is cleared.
 1614: 
 1615: =item *
 1616: 
 1617: SIGUSR1
 1618: 
 1619: Parent signal assignment:
 1620:  $SIG{USR1} = \&USRMAN;
 1621: 
 1622: Child signal assignment:
 1623:  $SIG{USR1}= \&logstatus;
 1624: 
 1625: Command-line invocations:
 1626:  B<kill> B<-s> SIGUSR1 I<PID>
 1627: 
 1628: Subroutine B<USRMAN>:
 1629:  When invoked for the B<lond> parent I<PID>,
 1630: SIGUSR1 is sent to all the children, and the status of
 1631: each connection is logged.
 1632: 
 1633: =item *
 1634: 
 1635: SIGCHLD
 1636: 
 1637: Parent signal assignment:
 1638:  $SIG{CHLD} = \&REAPER;
 1639: 
 1640: Child signal assignment:
 1641:  none
 1642: 
 1643: Command-line invocations:
 1644:  B<kill> B<-s> SIGCHLD I<PID>
 1645: 
 1646: Subroutine B<REAPER>:
 1647:  This is only invoked for the B<lond> parent I<PID>.
 1648: Information pertaining to the child is removed.
 1649: The socket port is cleaned up.
 1650: 
 1651: =back
 1652: 
 1653: B<SERVER-SIDE ACTIVITIES>
 1654: 
 1655: Server-side information can be accepted in an encrypted or non-encrypted
 1656: method.
 1657: 
 1658: =over 4
 1659: 
 1660: =item ping
 1661: 
 1662: Query a client in the hosts.tab table; "Are you there?"
 1663: 
 1664: =item pong
 1665: 
 1666: Respond to a ping query.
 1667: 
 1668: =item ekey
 1669: 
 1670: Read in encrypted key, make cipher.  Respond with a buildkey.
 1671: 
 1672: =item load
 1673: 
 1674: Respond with CPU load based on a computation upon /proc/loadavg.
 1675: 
 1676: =item currentauth
 1677: 
 1678: Reply with current authentication information (only over an
 1679: encrypted channel).
 1680: 
 1681: =item auth
 1682: 
 1683: Only over an encrypted channel, reply as to whether a user's
 1684: authentication information can be validated.
 1685: 
 1686: =item passwd
 1687: 
 1688: Allow for a password to be set.
 1689: 
 1690: =item makeuser
 1691: 
 1692: Make a user.
 1693: 
 1694: =item passwd
 1695: 
 1696: Allow for authentication mechanism and password to be changed.
 1697: 
 1698: =item home
 1699: 
 1700: Respond to a question "are you the home for a given user?"
 1701: 
 1702: =item update
 1703: 
 1704: Update contents of a subscribed resource.
 1705: 
 1706: =item unsubscribe
 1707: 
 1708: The server is unsubscribing from a resource.
 1709: 
 1710: =item subscribe
 1711: 
 1712: The server is subscribing to a resource.
 1713: 
 1714: =item log
 1715: 
 1716: Place in B<logs/lond.log>
 1717: 
 1718: =item put
 1719: 
 1720: stores hash in namespace
 1721: 
 1722: =item rolesput
 1723: 
 1724: put a role into a user's environment
 1725: 
 1726: =item get
 1727: 
 1728: returns hash with keys from array
 1729: reference filled in from namespace
 1730: 
 1731: =item eget
 1732: 
 1733: returns hash with keys from array
 1734: reference filled in from namesp (encrypts the return communication)
 1735: 
 1736: =item rolesget
 1737: 
 1738: get a role from a user's environment
 1739: 
 1740: =item del
 1741: 
 1742: deletes keys out of array from namespace
 1743: 
 1744: =item keys
 1745: 
 1746: returns namespace keys
 1747: 
 1748: =item dump
 1749: 
 1750: dumps the complete (or key matching regexp) namespace into a hash
 1751: 
 1752: =item store
 1753: 
 1754: stores hash permanently
 1755: for this url; hashref needs to be given and should be a \%hashname; the
 1756: remaining args aren't required and if they aren't passed or are '' they will
 1757: be derived from the ENV
 1758: 
 1759: =item restore
 1760: 
 1761: returns a hash for a given url
 1762: 
 1763: =item querysend
 1764: 
 1765: Tells client about the lonsql process that has been launched in response
 1766: to a sent query.
 1767: 
 1768: =item queryreply
 1769: 
 1770: Accept information from lonsql and make appropriate storage in temporary
 1771: file space.
 1772: 
 1773: =item idput
 1774: 
 1775: Defines usernames as corresponding to IDs.  (These "IDs" are unique identifiers
 1776: for each student, defined perhaps by the institutional Registrar.)
 1777: 
 1778: =item idget
 1779: 
 1780: Returns usernames corresponding to IDs.  (These "IDs" are unique identifiers
 1781: for each student, defined perhaps by the institutional Registrar.)
 1782: 
 1783: =item tmpput
 1784: 
 1785: Accept and store information in temporary space.
 1786: 
 1787: =item tmpget
 1788: 
 1789: Send along temporarily stored information.
 1790: 
 1791: =item ls
 1792: 
 1793: List part of a user's directory.
 1794: 
 1795: =item Hanging up (exit or init)
 1796: 
 1797: What to do when a client tells the server that they (the client)
 1798: are leaving the network.
 1799: 
 1800: =item unknown command
 1801: 
 1802: If B<lond> is sent an unknown command (not in the list above),
 1803: it replys to the client "unknown_cmd".
 1804: 
 1805: =item UNKNOWN CLIENT
 1806: 
 1807: If the anti-spoofing algorithm cannot verify the client,
 1808: the client is rejected (with a "refused" message sent
 1809: to the client, and the connection is closed.
 1810: 
 1811: =back
 1812: 
 1813: =head1 PREREQUISITES
 1814: 
 1815: IO::Socket
 1816: IO::File
 1817: Apache::File
 1818: Symbol
 1819: POSIX
 1820: Crypt::IDEA
 1821: LWP::UserAgent()
 1822: GDBM_File
 1823: Authen::Krb4
 1824: 
 1825: =head1 COREQUISITES
 1826: 
 1827: =head1 OSNAMES
 1828: 
 1829: linux
 1830: 
 1831: =head1 SCRIPT CATEGORIES
 1832: 
 1833: Server/Process
 1834: 
 1835: =cut

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