File:  [LON-CAPA] / loncom / lonnet / perl / lonnet.pm
Revision 1.114: download - view: text, annotated - select for diffs
Thu Mar 22 15:14:42 2001 UTC (23 years, 4 months ago) by harris41
Branches: MAIN
CVS tags: HEAD
more passing of the custom metadata information -Scott

    1: # The LearningOnline Network
    2: # TCP networking package
    3: #
    4: # Functions for use by content handlers:
    5: #
    6: # metadata_query(sql-query-string,custom-metadata-regex) : 
    7: #                                    returns file handle of where sql and
    8: #                                    regex results will be stored for query
    9: # plaintext(short)   : plain text explanation of short term
   10: # fileembstyle(ext)  : embed style in page for file extension
   11: # filedescription(ext) : descriptor text for file extension
   12: # allowed(short,url) : returns codes for allowed actions 
   13: #                      F: full access
   14: #                      U,I,K: authentication modes (cxx only)
   15: #                      '': forbidden
   16: #                      1: user needs to choose course
   17: #                      2: browse allowed
   18: # definerole(rolename,sys,dom,cou) : define a custom role rolename
   19: #                      set privileges in format of lonTabs/roles.tab for
   20: #                      system, domain and course level, 
   21: # assignrole(udom,uname,url,role,end,start) : give a role to a user for the
   22: #                      level given by url. Optional start and end dates
   23: #                      (leave empty string or zero for "no date") 
   24: # assigncustomrole (udom,uname,url,rdom,rnam,rolename,end,start) : give a
   25: #                      custom role to a user for the level given by url.
   26: #                      Specify name and domain of role author, and role name
   27: # revokerole (udom,uname,url,role) : Revoke a role for url
   28: # revokecustomrole (udom,uname,url,rdom,rnam,rolename) : Revoke a custom role
   29: # appenv(hash)       : adds hash to session environment
   30: # delenv(varname)    : deletes all environment entries starting with varname
   31: # store(hash)        : stores hash permanently for this url
   32: # cstore(hash)       : critical store
   33: # restore            : returns hash for this url
   34: # eget(namesp,array) : returns hash with keys from array filled in from namesp
   35: # get(namesp,array)  : returns hash with keys from array filled in from namesp
   36: # del(namesp,array)  : deletes keys out of array from namesp
   37: # put(namesp,hash)   : stores hash in namesp
   38: # cput(namesp,hash)  : critical put
   39: # dump(namesp)       : dumps the complete namespace into a hash
   40: # ssi(url,hash)      : does a complete request cycle on url to localhost, posts
   41: #                      hash
   42: # coursedescription(id) : returns and caches course description for id
   43: # repcopy(filename)  : replicate file
   44: # dirlist(url)       : gets a directory listing
   45: # directcondval(index) : reading condition value of single condition from 
   46: #                        state string
   47: # condval(index)     : value of condition index based on state
   48: # EXT(name)          : value of a variable
   49: # symblist(map,hash) : Updates symbolic storage links
   50: # symbread([filename]) : returns the data handle (filename optional)
   51: # rndseed()          : returns a random seed 
   52: # receipt()          : returns a receipt to be given out to users 
   53: # getfile(filename)  : returns the contents of filename, or a -1 if it can't
   54: #                      be found, replicates and subscribes to the file
   55: # filelocation(dir,file) : returns a farily clean absolute reference to file 
   56: #                          from the directory dir
   57: # hreflocation(dir,file) : same as filelocation, but for hrefs
   58: # log(domain,user,home,msg) : write to permanent log for user
   59: # usection(domain,user,courseid) : output of section name/number or '' for
   60: #                                  "not in course" and '-1' for "no section"
   61: # userenvironment(domain,user,what) : puts out any environment parameter 
   62: #                                     for a user
   63: # idput(domain,hash) : writes IDs for users from hash (name=>id,name=>id)
   64: # idget(domain,array): returns hash with usernames (id=>name,id=>name) for
   65: #                      an array of IDs
   66: # idrget(domain,array): returns hash with IDs for usernames (name=>id,...) for
   67: #                       an array of names
   68: # metadata(file,entry): returns the metadata entry for a file. entry='keys'
   69: #                       returns a comma separated list of keys
   70: #
   71: # 6/1/99,6/2,6/10,6/11,6/12,6/14,6/26,6/28,6/29,6/30,
   72: # 7/1,7/2,7/9,7/10,7/12,7/14,7/15,7/19,
   73: # 11/8,11/16,11/18,11/22,11/23,12/22,
   74: # 01/06,01/13,02/24,02/28,02/29,
   75: # 03/01,03/02,03/06,03/07,03/13,
   76: # 04/05,05/29,05/31,06/01,
   77: # 06/05,06/26 Gerd Kortemeyer
   78: # 06/26 Ben Tyszka
   79: # 06/30,07/15,07/17,07/18,07/20,07/21,07/22,07/25 Gerd Kortemeyer
   80: # 08/14 Ben Tyszka
   81: # 08/22,08/28,08/31,09/01,09/02,09/04,09/05,09/25,09/28,09/30 Gerd Kortemeyer
   82: # 10/04 Gerd Kortemeyer
   83: # 10/04 Guy Albertelli
   84: # 10/06,10/09,10/10,10/11,10/14,10/20,10/23,10/25,10/26,10/27,10/28,10/29, 
   85: # 10/30,10/31,
   86: # 11/2,11/14,11/15,11/16,11/20,11/21,11/22,11/25,11/27,
   87: # 12/02,12/12,12/13,12/14,12/28,12/29 Gerd Kortemeyer
   88: # 05/01/01 Guy Albertelli
   89: # 05/01,06/01,09/01 Gerd Kortemeyer
   90: # 09/01 Guy Albertelli
   91: # 09/01,10/01,11/01 Gerd Kortemeyer
   92: # 02/27/01 Scott Harrison
   93: # 3/2 Gerd Kortemeyer
   94: # 3/15 Scott Harrison
   95: # 3/19,3/20 Gerd Kortemeyer
   96: # 3/22 Scott Harrison
   97: 
   98: package Apache::lonnet;
   99: 
  100: use strict;
  101: use Apache::File;
  102: use LWP::UserAgent();
  103: use HTTP::Headers;
  104: use vars 
  105: qw(%perlvar %hostname %homecache %spareid %hostdom %libserv %pr %prp %fe %fd $readit %metacache);
  106: use IO::Socket;
  107: use GDBM_File;
  108: use Apache::Constants qw(:common :http);
  109: use HTML::TokeParser;
  110: use Fcntl qw(:flock);
  111: 
  112: # --------------------------------------------------------------------- Logging
  113: 
  114: sub logthis {
  115:     my $message=shift;
  116:     my $execdir=$perlvar{'lonDaemons'};
  117:     my $now=time;
  118:     my $local=localtime($now);
  119:     my $fh=Apache::File->new(">>$execdir/logs/lonnet.log");
  120:     print $fh "$local ($$): $message\n";
  121:     return 1;
  122: }
  123: 
  124: sub logperm {
  125:     my $message=shift;
  126:     my $execdir=$perlvar{'lonDaemons'};
  127:     my $now=time;
  128:     my $local=localtime($now);
  129:     my $fh=Apache::File->new(">>$execdir/logs/lonnet.perm.log");
  130:     print $fh "$now:$message:$local\n";
  131:     return 1;
  132: }
  133: 
  134: # -------------------------------------------------- Non-critical communication
  135: sub subreply {
  136:     my ($cmd,$server)=@_;
  137:     my $peerfile="$perlvar{'lonSockDir'}/$server";
  138:     my $client=IO::Socket::UNIX->new(Peer    =>"$peerfile",
  139:                                      Type    => SOCK_STREAM,
  140:                                      Timeout => 10)
  141:        or return "con_lost";
  142:     print $client "$cmd\n";
  143:     my $answer=<$client>;
  144:     if (!$answer) { $answer="con_lost"; }
  145:     chomp($answer);
  146:     return $answer;
  147: }
  148: 
  149: sub reply {
  150:     my ($cmd,$server)=@_;
  151:     my $answer=subreply($cmd,$server);
  152:     if ($answer eq 'con_lost') { $answer=subreply($cmd,$server); }
  153:     if (($answer=~/^refused/) || ($answer=~/^rejected/)) {
  154:        &logthis("<font color=blue>WARNING:".
  155:                 " $cmd to $server returned $answer</font>");
  156:     }
  157:     return $answer;
  158: }
  159: 
  160: # ----------------------------------------------------------- Send USR1 to lonc
  161: 
  162: sub reconlonc {
  163:     my $peerfile=shift;
  164:     &logthis("Trying to reconnect for $peerfile");
  165:     my $loncfile="$perlvar{'lonDaemons'}/logs/lonc.pid";
  166:     if (my $fh=Apache::File->new("$loncfile")) {
  167: 	my $loncpid=<$fh>;
  168:         chomp($loncpid);
  169:         if (kill 0 => $loncpid) {
  170: 	    &logthis("lonc at pid $loncpid responding, sending USR1");
  171:             kill USR1 => $loncpid;
  172:             sleep 1;
  173:             if (-e "$peerfile") { return; }
  174:             &logthis("$peerfile still not there, give it another try");
  175:             sleep 5;
  176:             if (-e "$peerfile") { return; }
  177:             &logthis(
  178:   "<font color=blue>WARNING: $peerfile still not there, giving up</font>");
  179:         } else {
  180: 	    &logthis(
  181:                "<font color=blue>WARNING:".
  182:                " lonc at pid $loncpid not responding, giving up</font>");
  183:         }
  184:     } else {
  185:      &logthis('<font color=blue>WARNING: lonc not running, giving up</font>');
  186:     }
  187: }
  188: 
  189: # ------------------------------------------------------ Critical communication
  190: 
  191: sub critical {
  192:     my ($cmd,$server)=@_;
  193:     unless ($hostname{$server}) {
  194:         &logthis("<font color=blue>WARNING:".
  195:                " Critical message to unknown server ($server)</font>");
  196:         return 'no_such_host';
  197:     }
  198:     my $answer=reply($cmd,$server);
  199:     if ($answer eq 'con_lost') {
  200:         my $pingreply=reply('ping',$server);
  201: 	&reconlonc("$perlvar{'lonSockDir'}/$server");
  202:         my $pongreply=reply('pong',$server);
  203:         &logthis("Ping/Pong for $server: $pingreply/$pongreply");
  204:         $answer=reply($cmd,$server);
  205:         if ($answer eq 'con_lost') {
  206:             my $now=time;
  207:             my $middlename=$cmd;
  208:             $middlename=substr($middlename,0,16);
  209:             $middlename=~s/\W//g;
  210:             my $dfilename=
  211:              "$perlvar{'lonSockDir'}/delayed/$now.$middlename.$server";
  212:             {
  213:              my $dfh;
  214:              if ($dfh=Apache::File->new(">$dfilename")) {
  215:                 print $dfh "$cmd\n";
  216: 	     }
  217:             }
  218:             sleep 2;
  219:             my $wcmd='';
  220:             {
  221: 	     my $dfh;
  222:              if ($dfh=Apache::File->new("$dfilename")) {
  223:                 $wcmd=<$dfh>;
  224: 	     }
  225:             }
  226:             chomp($wcmd);
  227:             if ($wcmd eq $cmd) {
  228: 		&logthis("<font color=blue>WARNING: ".
  229:                          "Connection buffer $dfilename: $cmd</font>");
  230:                 &logperm("D:$server:$cmd");
  231: 	        return 'con_delayed';
  232:             } else {
  233:                 &logthis("<font color=red>CRITICAL:"
  234:                         ." Critical connection failed: $server $cmd</font>");
  235:                 &logperm("F:$server:$cmd");
  236:                 return 'con_failed';
  237:             }
  238:         }
  239:     }
  240:     return $answer;
  241: }
  242: 
  243: # ---------------------------------------------------------- Append Environment
  244: 
  245: sub appenv {
  246:     my %newenv=@_;
  247:     map {
  248: 	if (($newenv{$_}=~/^user\.role/) || ($newenv{$_}=~/^user\.priv/)) {
  249:             &logthis("<font color=blue>WARNING: ".
  250:                 "Attempt to modify environment ".$_." to ".$newenv{$_});
  251: 	    delete($newenv{$_});
  252:         } else {
  253:             $ENV{$_}=$newenv{$_};
  254:         }
  255:     } keys %newenv;
  256: 
  257:     my $lockfh;
  258:     unless ($lockfh=Apache::File->new("$ENV{'user.environment'}")) {
  259:        return 'error: '.$!;
  260:     }
  261:     unless (flock($lockfh,LOCK_EX)) {
  262:          &logthis("<font color=blue>WARNING: ".
  263:                   'Could not obtain exclusive lock in appenv: '.$!);
  264:          $lockfh->close();
  265:          return 'error: '.$!;
  266:     }
  267: 
  268:     my @oldenv;
  269:     {
  270:      my $fh;
  271:      unless ($fh=Apache::File->new("$ENV{'user.environment'}")) {
  272: 	return 'error: '.$!;
  273:      }
  274:      @oldenv=<$fh>;
  275:      $fh->close();
  276:     }
  277:     for (my $i=0; $i<=$#oldenv; $i++) {
  278:         chomp($oldenv[$i]);
  279:         if ($oldenv[$i] ne '') {
  280:            my ($name,$value)=split(/=/,$oldenv[$i]);
  281:            unless (defined($newenv{$name})) {
  282: 	      $newenv{$name}=$value;
  283: 	   }
  284:         }
  285:     }
  286:     {
  287:      my $fh;
  288:      unless ($fh=Apache::File->new(">$ENV{'user.environment'}")) {
  289: 	return 'error';
  290:      }
  291:      my $newname;
  292:      foreach $newname (keys %newenv) {
  293: 	 print $fh "$newname=$newenv{$newname}\n";
  294:      }
  295:      $fh->close();
  296:     }
  297: 
  298:     $lockfh->close();
  299:     return 'ok';
  300: }
  301: # ----------------------------------------------------- Delete from Environment
  302: 
  303: sub delenv {
  304:     my $delthis=shift;
  305:     my %newenv=();
  306:     if (($delthis=~/user\.role/) || ($delthis=~/user\.priv/)) {
  307:         &logthis("<font color=blue>WARNING: ".
  308:                 "Attempt to delete from environment ".$delthis);
  309:         return 'error';
  310:     }
  311:     my @oldenv;
  312:     {
  313:      my $fh;
  314:      unless ($fh=Apache::File->new("$ENV{'user.environment'}")) {
  315: 	return 'error';
  316:      }
  317:      unless (flock($fh,LOCK_SH)) {
  318:          &logthis("<font color=blue>WARNING: ".
  319:                   'Could not obtain shared lock in delenv: '.$!);
  320:          $fh->close();
  321:          return 'error: '.$!;
  322:      }
  323:      @oldenv=<$fh>;
  324:      $fh->close();
  325:     }
  326:     {
  327:      my $fh;
  328:      unless ($fh=Apache::File->new(">$ENV{'user.environment'}")) {
  329: 	return 'error';
  330:      }
  331:      unless (flock($fh,LOCK_EX)) {
  332:          &logthis("<font color=blue>WARNING: ".
  333:                   'Could not obtain exclusive lock in delenv: '.$!);
  334:          $fh->close();
  335:          return 'error: '.$!;
  336:      }
  337:      map {
  338: 	 unless ($_=~/^$delthis/) { print $fh $_; }
  339:      } @oldenv;
  340:      $fh->close();
  341:     }
  342:     return 'ok';
  343: }
  344: 
  345: # ------------------------------ Find server with least workload from spare.tab
  346: 
  347: sub spareserver {
  348:     my $tryserver;
  349:     my $spareserver='';
  350:     my $lowestserver=100;
  351:     foreach $tryserver (keys %spareid) {
  352:        my $answer=reply('load',$tryserver);
  353:        if (($answer =~ /\d/) && ($answer<$lowestserver)) {
  354: 	   $spareserver="http://$hostname{$tryserver}";
  355:            $lowestserver=$answer;
  356:        }
  357:     }    
  358:     return $spareserver;
  359: }
  360: 
  361: # --------- Try to authenticate user from domain's lib servers (first this one)
  362: 
  363: sub authenticate {
  364:     my ($uname,$upass,$udom)=@_;
  365:     $upass=escape($upass);
  366:     if (($perlvar{'lonRole'} eq 'library') && 
  367:         ($udom eq $perlvar{'lonDefDomain'})) {
  368:     my $answer=reply("encrypt:auth:$udom:$uname:$upass",$perlvar{'lonHostID'});
  369:         if ($answer =~ /authorized/) {
  370:               if ($answer eq 'authorized') {
  371:                  &logthis("User $uname at $udom authorized by local server"); 
  372:                  return $perlvar{'lonHostID'}; 
  373:               }
  374:               if ($answer eq 'non_authorized') {
  375:                  &logthis("User $uname at $udom rejected by local server"); 
  376:                  return 'no_host'; 
  377:               }
  378: 	}
  379:     }
  380: 
  381:     my $tryserver;
  382:     foreach $tryserver (keys %libserv) {
  383: 	if ($hostdom{$tryserver} eq $udom) {
  384:            my $answer=reply("encrypt:auth:$udom:$uname:$upass",$tryserver);
  385:            if ($answer =~ /authorized/) {
  386:               if ($answer eq 'authorized') {
  387:                  &logthis("User $uname at $udom authorized by $tryserver"); 
  388:                  return $tryserver; 
  389:               }
  390:               if ($answer eq 'non_authorized') {
  391:                  &logthis("User $uname at $udom rejected by $tryserver");
  392:                  return 'no_host';
  393:               } 
  394: 	   }
  395:        }
  396:     }
  397:     &logthis("User $uname at $udom could not be authenticated");    
  398:     return 'no_host';
  399: }
  400: 
  401: # ---------------------- Find the homebase for a user from domain's lib servers
  402: 
  403: sub homeserver {
  404:     my ($uname,$udom)=@_;
  405: 
  406:     my $index="$uname:$udom";
  407:     if ($homecache{$index}) { return "$homecache{$index}"; }
  408: 
  409:     my $tryserver;
  410:     foreach $tryserver (keys %libserv) {
  411: 	if ($hostdom{$tryserver} eq $udom) {
  412:            my $answer=reply("home:$udom:$uname",$tryserver);
  413:            if ($answer eq 'found') { 
  414: 	      $homecache{$index}=$tryserver;
  415:               return $tryserver; 
  416: 	   }
  417:        }
  418:     }    
  419:     return 'no_host';
  420: }
  421: 
  422: # ------------------------------------- Find the usernames behind a list of IDs
  423: 
  424: sub idget {
  425:     my ($udom,@ids)=@_;
  426:     my %returnhash=();
  427:     
  428:     my $tryserver;
  429:     foreach $tryserver (keys %libserv) {
  430:        if ($hostdom{$tryserver} eq $udom) {
  431: 	  my $idlist=join('&',@ids);
  432:           $idlist=~tr/A-Z/a-z/; 
  433: 	  my $reply=&reply("idget:$udom:".$idlist,$tryserver);
  434:           my @answer=();
  435:           if (($reply ne 'con_lost') && ($reply!~/^error\:/)) {
  436: 	      @answer=split(/\&/,$reply);
  437:           }                    ;
  438:           my $i;
  439:           for ($i=0;$i<=$#ids;$i++) {
  440:               if ($answer[$i]) {
  441: 		  $returnhash{$ids[$i]}=$answer[$i];
  442:               } 
  443:           }
  444:        }
  445:     }    
  446:     return %returnhash;
  447: }
  448: 
  449: # ------------------------------------- Find the IDs behind a list of usernames
  450: 
  451: sub idrget {
  452:     my ($udom,@unames)=@_;
  453:     my %returnhash=();
  454:     map {
  455:         $returnhash{$_}=(&userenvironment($udom,$_,'id'))[1];
  456:     } @unames;
  457:     return %returnhash;
  458: }
  459: 
  460: # ------------------------------- Store away a list of names and associated IDs
  461: 
  462: sub idput {
  463:     my ($udom,%ids)=@_;
  464:     my %servers=();
  465:     map {
  466:         my $uhom=&homeserver($_,$udom);
  467:         if ($uhom ne 'no_host') {
  468:             my $id=&escape($ids{$_});
  469:             $id=~tr/A-Z/a-z/;
  470:             my $unam=&escape($_);
  471: 	    if ($servers{$uhom}) {
  472: 		$servers{$uhom}.='&'.$id.'='.$unam;
  473:             } else {
  474:                 $servers{$uhom}=$id.'='.$unam;
  475:             }
  476:             &critical('put:'.$udom.':'.$unam.':environment:id='.$id,$uhom);
  477:         }
  478:     } keys %ids;
  479:     map {
  480:         &critical('idput:'.$udom.':'.$servers{$_},$_);
  481:     } keys %servers;
  482: }
  483: 
  484: # ------------------------------------- Find the section of student in a course
  485: 
  486: sub usection {
  487:     my ($udom,$unam,$courseid)=@_;
  488:     $courseid=~s/\_/\//g;
  489:     $courseid=~s/^(\w)/\/$1/;
  490:     map {
  491:         my ($key,$value)=split(/\=/,$_);
  492:         $key=&unescape($key);
  493:         if ($key=~/^$courseid(?:\/)*(\w+)*\_st$/) {
  494:             my $section=$1;
  495:             if ($key eq $courseid.'_st') { $section=''; }
  496: 	    my ($dummy,$end,$start)=split(/\_/,&unescape($value));
  497:             my $now=time;
  498:             my $notactive=0;
  499:             if ($start) {
  500: 		if ($now<$start) { $notactive=1; }
  501:             }
  502:             if ($end) {
  503:                 if ($now>$end) { $notactive=1; }
  504:             } 
  505:             unless ($notactive) { return $section; }
  506:         }
  507:     } split(/\&/,&reply('dump:'.$udom.':'.$unam.':roles',
  508:                         &homeserver($unam,$udom)));
  509:     return '-1';
  510: }
  511: 
  512: # ------------------------------------- Read an entry from a user's environment
  513: 
  514: sub userenvironment {
  515:     my ($udom,$unam,@what)=@_;
  516:     my %returnhash=();
  517:     my @answer=split(/\&/,
  518:                 &reply('get:'.$udom.':'.$unam.':environment:'.join('&',@what),
  519:                       &homeserver($unam,$udom)));
  520:     my $i;
  521:     for ($i=0;$i<=$#what;$i++) {
  522: 	$returnhash{$what[$i]}=&unescape($answer[$i]);
  523:     }
  524:     return %returnhash;
  525: }
  526: 
  527: # ----------------------------- Subscribe to a resource, return URL if possible
  528: 
  529: sub subscribe {
  530:     my $fname=shift;
  531:     my $author=$fname;
  532:     $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
  533:     my ($udom,$uname)=split(/\//,$author);
  534:     my $home=homeserver($uname,$udom);
  535:     if (($home eq 'no_host') || ($home eq $perlvar{'lonHostID'})) { 
  536:         return 'not_found'; 
  537:     }
  538:     my $answer=reply("sub:$fname",$home);
  539:     if (($answer eq 'con_lost') || ($answer eq 'rejected')) {
  540: 	$answer.=' by '.$home;
  541:     }
  542:     return $answer;
  543: }
  544:     
  545: # -------------------------------------------------------------- Replicate file
  546: 
  547: sub repcopy {
  548:     my $filename=shift;
  549:     $filename=~s/\/+/\//g;
  550:     my $transname="$filename.in.transfer";
  551:     if ((-e $filename) || (-e $transname)) { return OK; }
  552:     my $remoteurl=subscribe($filename);
  553:     if ($remoteurl =~ /^con_lost by/) {
  554: 	   &logthis("Subscribe returned $remoteurl: $filename");
  555:            return HTTP_SERVICE_UNAVAILABLE;
  556:     } elsif ($remoteurl eq 'not_found') {
  557: 	   &logthis("Subscribe returned not_found: $filename");
  558: 	   return HTTP_NOT_FOUND;
  559:     } elsif ($remoteurl =~ /^rejected by/) {
  560: 	   &logthis("Subscribe returned $remoteurl: $filename");
  561:            return FORBIDDEN;
  562:     } elsif ($remoteurl eq 'directory') {
  563:            return OK;
  564:     } else {
  565:            my @parts=split(/\//,$filename);
  566:            my $path="/$parts[1]/$parts[2]/$parts[3]/$parts[4]";
  567:            if ($path ne "$perlvar{'lonDocRoot'}/res") {
  568:                &logthis("Malconfiguration for replication: $filename");
  569: 	       return HTTP_BAD_REQUEST;
  570:            }
  571:            my $count;
  572:            for ($count=5;$count<$#parts;$count++) {
  573:                $path.="/$parts[$count]";
  574:                if ((-e $path)!=1) {
  575: 		   mkdir($path,0777);
  576:                }
  577:            }
  578:            my $ua=new LWP::UserAgent;
  579:            my $request=new HTTP::Request('GET',"$remoteurl");
  580:            my $response=$ua->request($request,$transname);
  581:            if ($response->is_error()) {
  582: 	       unlink($transname);
  583:                my $message=$response->status_line;
  584:                &logthis("<font color=blue>WARNING:"
  585:                        ." LWP get: $message: $filename</font>");
  586:                return HTTP_SERVICE_UNAVAILABLE;
  587:            } else {
  588: 	       if ($remoteurl!~/\.meta$/) {
  589:                   my $mrequest=new HTTP::Request('GET',$remoteurl.'.meta');
  590:                   my $mresponse=$ua->request($mrequest,$filename.'.meta');
  591:                   if ($mresponse->is_error()) {
  592: 		      unlink($filename.'.meta');
  593:                       &logthis(
  594:                      "<font color=yellow>INFO: No metadata: $filename</font>");
  595:                   }
  596: 	       }
  597:                rename($transname,$filename);
  598:                return OK;
  599:            }
  600:     }
  601: }
  602: 
  603: # --------------------------------------------------------- Server Side Include
  604: 
  605: sub ssi {
  606: 
  607:     my ($fn,%form)=@_;
  608: 
  609:     my $ua=new LWP::UserAgent;
  610:     
  611:     my $request;
  612:     
  613:     if (%form) {
  614:       $request=new HTTP::Request('POST',"http://".$ENV{'HTTP_HOST'}.$fn);
  615:       $request->content(join '&', map { "$_=$form{$_}" } keys %form);
  616:     } else {
  617:       $request=new HTTP::Request('GET',"http://".$ENV{'HTTP_HOST'}.$fn);
  618:     }
  619: 
  620:     $request->header(Cookie => $ENV{'HTTP_COOKIE'});
  621:     my $response=$ua->request($request);
  622: 
  623:     return $response->content;
  624: }
  625: 
  626: # ------------------------------------------------------------------------- Log
  627: 
  628: sub log {
  629:     my ($dom,$nam,$hom,$what)=@_;
  630:     return critical("log:$dom:$nam:$what",$hom);
  631: }
  632: 
  633: # --------------------------------------------- Set Expire Date for Spreadsheet
  634: 
  635: sub expirespread {
  636:     my ($uname,$udom,$stype,$usymb)=@_;
  637:     my $cid=$ENV{'request.course.id'}; 
  638:     if ($cid) {
  639:        my $now=time;
  640:        my $key=$uname.':'.$udom.':'.$stype.':'.$usymb;
  641:        return &reply('put:'.$ENV{'course.'.$cid.'.domain'}.':'.
  642:                             $ENV{'course.'.$cid.'.num'}.
  643: 	        	    ':nohist_expirationdates:'.
  644:                             &escape($key).'='.$now,
  645:                             $ENV{'course.'.$cid.'.home'})
  646:     }
  647:     return 'ok';
  648: }
  649: 
  650: # ----------------------------------------------------- Devalidate Spreadsheets
  651: 
  652: sub devalidate {
  653:     my $symb=shift;
  654:     my $cid=$ENV{'request.course.id'}; 
  655:     if ($cid) {
  656: 	my $key=$ENV{'user.name'}.':'.$ENV{'user.domain'}.':';
  657:         my $status=
  658:           &reply('del:'.$ENV{'course.'.$cid.'.domain'}.':'.
  659:                         $ENV{'course.'.$cid.'.num'}.
  660: 	                ':nohist_calculatedsheets:'.
  661:                         &escape($key.'studentcalc:'),
  662:                         $ENV{'course.'.$cid.'.home'})
  663:           .' '.
  664:           &reply('del:'.$ENV{'user.domain'}.':'.
  665:                         $ENV{'user.name'}.
  666: 		        ':nohist_calculatedsheets_'.$cid.':'.
  667:                         &escape($key.'assesscalc:'.$symb),
  668:                         $ENV{'user.home'});
  669:         unless ($status eq 'ok ok') {
  670:            &logthis('Could not devalidate spreadsheet '.
  671:                     $ENV{'user.name'}.' at '.$ENV{'user.domain'}.' for '.
  672: 		    $symb.': '.$status);
  673:         } 
  674:     }
  675: }
  676: 
  677: # ----------------------------------------------------------------------- Store
  678: 
  679: sub store {
  680:     my %storehash=@_;
  681:     my $symb;
  682:     unless ($symb=&symbread()) { return ''; }
  683: 
  684:     &devalidate($symb);
  685: 
  686:     $symb=escape($symb);
  687:     my $namespace;
  688:     unless ($namespace=$ENV{'request.course.id'}) { return ''; }
  689:     my $namevalue='';
  690:     map {
  691:         $namevalue.=escape($_).'='.escape($storehash{$_}).'&';
  692:     } keys %storehash;
  693:     $namevalue=~s/\&$//;
  694:     return reply(
  695:      "store:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$symb:$namevalue",
  696: 		 "$ENV{'user.home'}");
  697: }
  698: 
  699: # -------------------------------------------------------------- Critical Store
  700: 
  701: sub cstore {
  702:     my %storehash=@_;
  703:     my $symb;
  704:     unless ($symb=&symbread()) { return ''; }
  705: 
  706:     &devalidate($symb);
  707: 
  708:     $symb=escape($symb);
  709:     my $namespace;
  710:     unless ($namespace=$ENV{'request.course.id'}) { return ''; }
  711:     my $namevalue='';
  712:     map {
  713:         $namevalue.=escape($_).'='.escape($storehash{$_}).'&';
  714:     } keys %storehash;
  715:     $namevalue=~s/\&$//;
  716:     return critical(
  717:      "store:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$symb:$namevalue",
  718: 		 "$ENV{'user.home'}");
  719: }
  720: 
  721: # --------------------------------------------------------------------- Restore
  722: 
  723: sub restore {
  724:     my $symb;
  725:     unless ($symb=escape(&symbread())) { return ''; }
  726:     my $namespace;
  727:     unless ($namespace=$ENV{'request.course.id'}) { return ''; }
  728:     my $answer=reply(
  729:               "restore:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$symb",
  730:               "$ENV{'user.home'}");
  731:     my %returnhash=();
  732:     map {
  733: 	my ($name,$value)=split(/\=/,$_);
  734:         $returnhash{&unescape($name)}=&unescape($value);
  735:     } split(/\&/,$answer);
  736:     my $version;
  737:     for ($version=1;$version<=$returnhash{'version'};$version++) {
  738:        map {
  739:           $returnhash{$_}=$returnhash{$version.':'.$_};
  740:        } split(/\:/,$returnhash{$version.':keys'});
  741:     }
  742:     return %returnhash;
  743: }
  744: 
  745: # ---------------------------------------------------------- Course Description
  746: 
  747: sub coursedescription {
  748:     my $courseid=shift;
  749:     $courseid=~s/^\///;
  750:     $courseid=~s/\_/\//g;
  751:     my ($cdomain,$cnum)=split(/\//,$courseid);
  752:     my $chome=homeserver($cnum,$cdomain);
  753:     if ($chome ne 'no_host') {
  754:        my $rep=reply("dump:$cdomain:$cnum:environment",$chome);
  755:        if ($rep ne 'con_lost') {
  756:            my $normalid=$cdomain.'_'.$cnum;
  757:            my %envhash=();
  758:            my %returnhash=('home'   => $chome, 
  759:                            'domain' => $cdomain,
  760:                            'num'    => $cnum);
  761:            map {
  762:                my ($name,$value)=split(/\=/,$_);
  763:                $name=&unescape($name);
  764:                $value=&unescape($value);
  765:                $returnhash{$name}=$value;
  766:                $envhash{'course.'.$normalid.'.'.$name}=$value;
  767:            } split(/\&/,$rep);
  768:            $returnhash{'url'}='/res/'.declutter($returnhash{'url'});
  769:            $returnhash{'fn'}=$perlvar{'lonDaemons'}.'/tmp/'.
  770: 	       $ENV{'user.name'}.'_'.$cdomain.'_'.$cnum;
  771:            $envhash{'course.'.$normalid.'.last_cache'}=time;
  772:            $envhash{'course.'.$normalid.'.home'}=$chome;
  773:            $envhash{'course.'.$normalid.'.domain'}=$cdomain;
  774:            $envhash{'course.'.$normalid.'.num'}=$cnum;
  775:            &appenv(%envhash);
  776:            return %returnhash;
  777:        }
  778:     }
  779:     return ();
  780: }
  781: 
  782: # -------------------------------------------------------- Get user privileges
  783: 
  784: sub rolesinit {
  785:     my ($domain,$username,$authhost)=@_;
  786:     my $rolesdump=reply("dump:$domain:$username:roles",$authhost);
  787:     if (($rolesdump eq 'con_lost') || ($rolesdump eq '')) { return ''; }
  788:     my %allroles=();
  789:     my %thesepriv=();
  790:     my $now=time;
  791:     my $userroles="user.login.time=$now\n";
  792:     my $thesestr;
  793: 
  794:     if ($rolesdump ne '') {
  795:         map {
  796: 	  if ($_!~/^rolesdef\&/) {
  797:             my ($area,$role)=split(/=/,$_);
  798:             $area=~s/\_\w\w$//;
  799:             my ($trole,$tend,$tstart)=split(/_/,$role);
  800:             $userroles.='user.role.'.$trole.'.'.$area.'='.
  801:                         $tstart.'.'.$tend."\n";
  802:             if ($tend!=0) {
  803: 	        if ($tend<$now) {
  804: 	            $trole='';
  805:                 } 
  806:             }
  807:             if ($tstart!=0) {
  808:                 if ($tstart>$now) {
  809:                    $trole='';        
  810:                 }
  811:             }
  812:             if (($area ne '') && ($trole ne '')) {
  813: 	       my $spec=$trole.'.'.$area;
  814:                my ($tdummy,$tdomain,$trest)=split(/\//,$area);
  815:                if ($trole =~ /^cr\//) {
  816: 		   my ($rdummy,$rdomain,$rauthor,$rrole)=split(/\//,$trole);
  817:                    my $homsvr=homeserver($rauthor,$rdomain);
  818:                    if ($hostname{$homsvr} ne '') {
  819:                       my $roledef=
  820: 			  reply("get:$rdomain:$rauthor:roles:rolesdef_$rrole",
  821:                                 $homsvr);
  822:                       if (($roledef ne 'con_lost') && ($roledef ne '')) {
  823:                          my ($syspriv,$dompriv,$coursepriv)=
  824: 			     split(/\_/,unescape($roledef));
  825:  	                 $allroles{'cm./'}.=':'.$syspriv;
  826:                          $allroles{$spec.'./'}.=':'.$syspriv;
  827:                          if ($tdomain ne '') {
  828:                              $allroles{'cm./'.$tdomain.'/'}.=':'.$dompriv;
  829:                              $allroles{$spec.'./'.$tdomain.'/'}.=':'.$dompriv;
  830:                              if ($trest ne '') {
  831: 		                $allroles{'cm.'.$area}.=':'.$coursepriv;
  832: 		                $allroles{$spec.'.'.$area}.=':'.$coursepriv;
  833:                              }
  834: 	                 }
  835:                       }
  836:                    }
  837:                } else {
  838: 	           $allroles{'cm./'}.=':'.$pr{$trole.':s'};
  839: 	           $allroles{$spec.'./'}.=':'.$pr{$trole.':s'};
  840:                    if ($tdomain ne '') {
  841:                      $allroles{'cm./'.$tdomain.'/'}.=':'.$pr{$trole.':d'};
  842:                      $allroles{$spec.'./'.$tdomain.'/'}.=':'.$pr{$trole.':d'};
  843:                       if ($trest ne '') {
  844: 		          $allroles{'cm.'.$area}.=':'.$pr{$trole.':c'};
  845: 		          $allroles{$spec.'.'.$area}.=':'.$pr{$trole.':c'};
  846:                       }
  847: 	           }
  848: 	       }
  849:             }
  850:           } 
  851:         } split(/&/,$rolesdump);
  852:         map {
  853:             %thesepriv=();
  854:             map {
  855:                 if ($_ ne '') {
  856: 		    my ($privilege,$restrictions)=split(/&/,$_);
  857:                     if ($restrictions eq '') {
  858: 			$thesepriv{$privilege}='F';
  859:                     } else {
  860:                         if ($thesepriv{$privilege} ne 'F') {
  861: 			    $thesepriv{$privilege}.=$restrictions;
  862:                         }
  863:                     }
  864:                 }
  865:             } split(/:/,$allroles{$_});
  866:             $thesestr='';
  867:             map { $thesestr.=':'.$_.'&'.$thesepriv{$_}; } keys %thesepriv;
  868:             $userroles.='user.priv.'.$_.'='.$thesestr."\n";
  869:         } keys %allroles;            
  870:     }
  871:     return $userroles;  
  872: }
  873: 
  874: # --------------------------------------------------------------- get interface
  875: 
  876: sub get {
  877:    my ($namespace,@storearr)=@_;
  878:    my $items='';
  879:    map {
  880:        $items.=escape($_).'&';
  881:    } @storearr;
  882:    $items=~s/\&$//;
  883:  my $rep=reply("get:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$items",
  884:                  $ENV{'user.home'});
  885:    my @pairs=split(/\&/,$rep);
  886:    my %returnhash=();
  887:    my $i=0;
  888:    map {
  889:       $returnhash{$_}=unescape($pairs[$i]);
  890:       $i++;
  891:    } @storearr;
  892:    return %returnhash;
  893: }
  894: 
  895: # --------------------------------------------------------------- del interface
  896: 
  897: sub del {
  898:    my ($namespace,@storearr)=@_;
  899:    my $items='';
  900:    map {
  901:        $items.=escape($_).'&';
  902:    } @storearr;
  903:    $items=~s/\&$//;
  904:    return reply("del:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$items",
  905:                  $ENV{'user.home'});
  906: }
  907: 
  908: # -------------------------------------------------------------- dump interface
  909: 
  910: sub dump {
  911:    my $namespace=shift;
  912:    my $rep=reply("dump:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace",
  913:                 $ENV{'user.home'});
  914:    my @pairs=split(/\&/,$rep);
  915:    my %returnhash=();
  916:    map {
  917:       my ($key,$value)=split(/=/,$_);
  918:       $returnhash{unescape($key)}=unescape($value);
  919:    } @pairs;
  920:    return %returnhash;
  921: }
  922: 
  923: # --------------------------------------------------------------- put interface
  924: 
  925: sub put {
  926:    my ($namespace,%storehash)=@_;
  927:    my $items='';
  928:    map {
  929:        $items.=escape($_).'='.escape($storehash{$_}).'&';
  930:    } keys %storehash;
  931:    $items=~s/\&$//;
  932:    return reply("put:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$items",
  933:                  $ENV{'user.home'});
  934: }
  935: 
  936: # ------------------------------------------------------ critical put interface
  937: 
  938: sub cput {
  939:    my ($namespace,%storehash)=@_;
  940:    my $items='';
  941:    map {
  942:        $items.=escape($_).'='.escape($storehash{$_}).'&';
  943:    } keys %storehash;
  944:    $items=~s/\&$//;
  945:    return critical
  946:            ("put:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$items",
  947:                  $ENV{'user.home'});
  948: }
  949: 
  950: # -------------------------------------------------------------- eget interface
  951: 
  952: sub eget {
  953:    my ($namespace,@storearr)=@_;
  954:    my $items='';
  955:    map {
  956:        $items.=escape($_).'&';
  957:    } @storearr;
  958:    $items=~s/\&$//;
  959:  my $rep=reply("eget:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$items",
  960:                  $ENV{'user.home'});
  961:    my @pairs=split(/\&/,$rep);
  962:    my %returnhash=();
  963:    my $i=0;
  964:    map {
  965:       $returnhash{$_}=unescape($pairs[$i]);
  966:       $i++;
  967:    } @storearr;
  968:    return %returnhash;
  969: }
  970: 
  971: # ------------------------------------------------- Check for a user privilege
  972: 
  973: sub allowed {
  974:     my ($priv,$uri)=@_;
  975:     $uri=&declutter($uri);
  976: 
  977: # Free bre access to adm and meta resources
  978: 
  979:     if ((($uri=~/^adm\//) || ($uri=~/\.meta$/)) && ($priv eq 'bre')) {
  980: 	return 'F';
  981:     }
  982: 
  983:     my $thisallowed='';
  984:     my $statecond=0;
  985:     my $courseprivid='';
  986: 
  987: # Course
  988: 
  989:     if ($ENV{'user.priv.'.$ENV{'request.role'}.'./'}=~/$priv\&([^\:]*)/) {
  990:        $thisallowed.=$1;
  991:     }
  992: 
  993: # Domain
  994: 
  995:     if ($ENV{'user.priv.'.$ENV{'request.role'}.'./'.(split(/\//,$uri))[0].'/'}
  996:        =~/$priv\&([^\:]*)/) {
  997:        $thisallowed.=$1;
  998:     }
  999: 
 1000: # Course: uri itself is a course
 1001:     my $courseuri=$uri;
 1002:     $courseuri=~s/\_(\d)/\/$1/;
 1003:     $courseuri=~s/^([^\/])/\/$1/;
 1004: 
 1005:     if ($ENV{'user.priv.'.$ENV{'request.role'}.'.'.$courseuri}
 1006:        =~/$priv\&([^\:]*)/) {
 1007:        $thisallowed.=$1;
 1008:     }
 1009: 
 1010: # Full access at system, domain or course-wide level? Exit.
 1011: 
 1012:     if ($thisallowed=~/F/) {
 1013: 	return 'F';
 1014:     }
 1015: 
 1016: # If this is generating or modifying users, exit with special codes
 1017: 
 1018:     if (':csu:cdc:ccc:cin:cta:cep:ccr:cst:cad:cli:cau:cdg:'=~/\:$priv\:/) {
 1019: 	return $thisallowed;
 1020:     }
 1021: #
 1022: # Gathered so far: system, domain and course wide privileges
 1023: #
 1024: # Course: See if uri or referer is an individual resource that is part of 
 1025: # the course
 1026: 
 1027:     if ($ENV{'request.course.id'}) {
 1028:        $courseprivid=$ENV{'request.course.id'};
 1029:        if ($ENV{'request.course.sec'}) {
 1030:           $courseprivid.='/'.$ENV{'request.course.sec'};
 1031:        }
 1032:        $courseprivid=~s/\_/\//;
 1033:        my $checkreferer=1;
 1034:        my @uriparts=split(/\//,$uri);
 1035:        my $filename=$uriparts[$#uriparts];
 1036:        my $pathname=$uri;
 1037:        $pathname=~s/\/$filename$//;
 1038:        if ($ENV{'acc.res.'.$ENV{'request.course.id'}.'.'.$pathname}=~
 1039:            /\&$filename\:([\d\|]+)\&/) {
 1040:            $statecond=$1;
 1041:            if ($ENV{'user.priv.'.$ENV{'request.role'}.'./'.$courseprivid}
 1042:                =~/$priv\&([^\:]*)/) {
 1043:                $thisallowed.=$1;
 1044:                $checkreferer=0;
 1045:            }
 1046:        }
 1047:        
 1048:        if (($ENV{'HTTP_REFERER'}) && ($checkreferer)) {
 1049: 	  my $refuri=$ENV{'HTTP_REFERER'};
 1050:           $refuri=~s/^http\:\/\/$ENV{'request.host'}//i;
 1051:           $refuri=&declutter($refuri);
 1052:           my @uriparts=split(/\//,$refuri);
 1053:           my $filename=$uriparts[$#uriparts];
 1054:           my $pathname=$refuri;
 1055:           $pathname=~s/\/$filename$//;
 1056:           my @filenameparts=split(/\./,$uri);
 1057:           if (&fileembstyle($filenameparts[$#filenameparts]) ne 'ssi') {
 1058:             if ($ENV{'acc.res.'.$ENV{'request.course.id'}.'.'.$pathname}=~
 1059:               /\&$filename\:([\d\|]+)\&/) {
 1060:               my $refstatecond=$1;
 1061:               if ($ENV{'user.priv.'.$ENV{'request.role'}.'./'.$courseprivid}
 1062:                   =~/$priv\&([^\:]*)/) {
 1063:                   $thisallowed.=$1;
 1064:                   $uri=$refuri;
 1065:                   $statecond=$refstatecond;
 1066:               }
 1067:             }
 1068:           }
 1069:        }
 1070:    }
 1071: 
 1072: #
 1073: # Gathered now: all privileges that could apply, and condition number
 1074: # 
 1075: #
 1076: # Full or no access?
 1077: #
 1078: 
 1079:     if ($thisallowed=~/F/) {
 1080: 	return 'F';
 1081:     }
 1082: 
 1083:     unless ($thisallowed) {
 1084:         return '';
 1085:     }
 1086: 
 1087: # Restrictions exist, deal with them
 1088: #
 1089: #   C:according to course preferences
 1090: #   R:according to resource settings
 1091: #   L:unless locked
 1092: #   X:according to user session state
 1093: #
 1094: 
 1095: # Possibly locked functionality, check all courses
 1096: # Locks might take effect only after 10 minutes cache expiration for other
 1097: # courses, and 2 minutes for current course
 1098: 
 1099:     my $envkey;
 1100:     if ($thisallowed=~/L/) {
 1101:         foreach $envkey (keys %ENV) {
 1102:            if ($envkey=~/^user\.role\.(st|ta)\.([^\.]*)/) {
 1103:                my $courseid=$2;
 1104:                my $roleid=$1.'.'.$2;
 1105:                $courseid=~s/^\///;
 1106:                my $expiretime=600;
 1107:                if ($ENV{'request.role'} eq $roleid) {
 1108: 		  $expiretime=120;
 1109:                }
 1110: 	       my ($cdom,$cnum,$csec)=split(/\//,$courseid);
 1111:                my $prefix='course.'.$cdom.'_'.$cnum.'.';
 1112:                if ((time-$ENV{$prefix.'last_cache'})>$expiretime) {
 1113: 		   &coursedescription($courseid);
 1114:                }
 1115:                if (($ENV{$prefix.'res.'.$uri.'.lock.sections'}=~/\,$csec\,/)
 1116:                 || ($ENV{$prefix.'res.'.$uri.'.lock.sections'} eq 'all')) {
 1117: 		   if ($ENV{$prefix.'res.'.$uri.'.lock.expire'}>time) {
 1118:                        &log($ENV{'user.domain'},$ENV{'user.name'},
 1119:                             $ENV{'user.host'},
 1120:                             'Locked by res: '.$priv.' for '.$uri.' due to '.
 1121:                             $cdom.'/'.$cnum.'/'.$csec.' expire '.
 1122:                             $ENV{$prefix.'priv.'.$priv.'.lock.expire'});
 1123: 		       return '';
 1124:                    }
 1125:                }
 1126:                if (($ENV{$prefix.'priv.'.$priv.'.lock.sections'}=~/\,$csec\,/)
 1127:                 || ($ENV{$prefix.'priv.'.$priv.'.lock.sections'} eq 'all')) {
 1128: 		   if ($ENV{'priv.'.$priv.'.lock.expire'}>time) {
 1129:                        &log($ENV{'user.domain'},$ENV{'user.name'},
 1130:                             $ENV{'user.host'},
 1131:                             'Locked by priv: '.$priv.' for '.$uri.' due to '.
 1132:                             $cdom.'/'.$cnum.'/'.$csec.' expire '.
 1133:                             $ENV{$prefix.'priv.'.$priv.'.lock.expire'});
 1134: 		       return '';
 1135:                    }
 1136:                }
 1137: 	   }
 1138:        }
 1139:     }
 1140:    
 1141: #
 1142: # Rest of the restrictions depend on selected course
 1143: #
 1144: 
 1145:     unless ($ENV{'request.course.id'}) {
 1146:        return '1';
 1147:     }
 1148: 
 1149: #
 1150: # Now user is definitely in a course
 1151: #
 1152: 
 1153: 
 1154: # Course preferences
 1155: 
 1156:    if ($thisallowed=~/C/) {
 1157:        my $rolecode=(split(/\./,$ENV{'request.role'}))[0];
 1158:        if ($ENV{'course.'.$ENV{'request.course.id'}.'.'.$priv.'.roles.denied'}
 1159: 	   =~/\,$rolecode\,/) {
 1160:            &log($ENV{'user.domain'},$ENV{'user.name'},$ENV{'user.host'},
 1161:                 'Denied by role: '.$priv.' for '.$uri.' as '.$rolecode.' in '.
 1162:                 $ENV{'request.course.id'});
 1163:            return '';
 1164:        }
 1165:    }
 1166: 
 1167: # Resource preferences
 1168: 
 1169:    if ($thisallowed=~/R/) {
 1170:        my $rolecode=(split(/\./,$ENV{'request.role'}))[0];
 1171:        my $filename=$perlvar{'lonDocRoot'}.'/res/'.$uri.'.meta';
 1172:        if (-e $filename) {
 1173:            my @content;
 1174:            {
 1175: 	     my $fh=Apache::File->new($filename);
 1176:              @content=<$fh>;
 1177: 	   }
 1178:            if (join('',@content)=~
 1179:                     /\<roledeny[^\>]*\>[^\<]*$rolecode[^\<]*\<\/roledeny\>/) {
 1180: 	       &log($ENV{'user.domain'},$ENV{'user.name'},$ENV{'user.host'},
 1181:                     'Denied by role: '.$priv.' for '.$uri.' as '.$rolecode);
 1182:            return '';
 1183: 
 1184:            }
 1185:        }
 1186:    }
 1187: 
 1188: # Restricted by state?
 1189: 
 1190:    if ($thisallowed=~/X/) {
 1191:       if (&condval($statecond)) {
 1192: 	 return '2';
 1193:       } else {
 1194:          return '';
 1195:       }
 1196:    }
 1197: 
 1198:    return 'F';
 1199: }
 1200: 
 1201: # ----------------------------------------------------------------- Define Role
 1202: 
 1203: sub definerole {
 1204:   if (allowed('mcr','/')) {
 1205:     my ($rolename,$sysrole,$domrole,$courole)=@_;
 1206:     map {
 1207: 	my ($crole,$cqual)=split(/\&/,$_);
 1208:         if ($pr{'cr:s'}!~/$crole/) { return "refused:s:$crole"; }
 1209:         if ($pr{'cr:s'}=~/$crole\&/) {
 1210: 	    if ($pr{'cr:s'}!~/$crole\&\w*$cqual/) { 
 1211:                return "refused:s:$crole&$cqual"; 
 1212:             }
 1213:         }
 1214:     } split('/',$sysrole);
 1215:     map {
 1216: 	my ($crole,$cqual)=split(/\&/,$_);
 1217:         if ($pr{'cr:d'}!~/$crole/) { return "refused:d:$crole"; }
 1218:         if ($pr{'cr:d'}=~/$crole\&/) {
 1219: 	    if ($pr{'cr:d'}!~/$crole\&\w*$cqual/) { 
 1220:                return "refused:d:$crole&$cqual"; 
 1221:             }
 1222:         }
 1223:     } split('/',$domrole);
 1224:     map {
 1225: 	my ($crole,$cqual)=split(/\&/,$_);
 1226:         if ($pr{'cr:c'}!~/$crole/) { return "refused:c:$crole"; }
 1227:         if ($pr{'cr:c'}=~/$crole\&/) {
 1228: 	    if ($pr{'cr:c'}!~/$crole\&\w*$cqual/) { 
 1229:                return "refused:c:$crole&$cqual"; 
 1230:             }
 1231:         }
 1232:     } split('/',$courole);
 1233:     my $command="encrypt:rolesput:$ENV{'user.domain'}:$ENV{'user.name'}:".
 1234:                 "$ENV{'user.domain'}:$ENV{'user.name'}:".
 1235: 	        "rolesdef_$rolename=".
 1236:                 escape($sysrole.'_'.$domrole.'_'.$courole);
 1237:     return reply($command,$ENV{'user.home'});
 1238:   } else {
 1239:     return 'refused';
 1240:   }
 1241: }
 1242: 
 1243: # ---------------- Make a metadata query against the network of library servers
 1244: 
 1245: sub metadata_query {
 1246:     my ($query,$custom)=@_;
 1247:     # need to put in a loop here and return list
 1248:     unless ($custom) {
 1249: 	my $reply=&reply("querysend:".&escape($query),'msul3');
 1250: 	return $reply;
 1251:     }
 1252:     else {
 1253: 	my $reply=&reply("querysend:".&escape($query).':'.
 1254: 			 &escape($customquery),'msul3');
 1255: 	return $reply;
 1256:     }
 1257:     my ($query)=@_;
 1258:     my $reply=&reply("querysend:".&escape($query),'msul3');
 1259: }
 1260: 
 1261: # ------------------------------------------------------------------ Plain Text
 1262: 
 1263: sub plaintext {
 1264:     my $short=shift;
 1265:     return $prp{$short};
 1266: }
 1267: 
 1268: # ------------------------------------------------------------------ Plain Text
 1269: 
 1270: sub fileembstyle {
 1271:     my $ending=shift;
 1272:     return $fe{$ending};
 1273: }
 1274: 
 1275: # ------------------------------------------------------------ Description Text
 1276: 
 1277: sub filedescription {
 1278:     my $ending=shift;
 1279:     return $fd{$ending};
 1280: }
 1281: 
 1282: # ----------------------------------------------------------------- Assign Role
 1283: 
 1284: sub assignrole {
 1285:     my ($udom,$uname,$url,$role,$end,$start)=@_;
 1286:     my $mrole;
 1287:     if ($role =~ /^cr\//) {
 1288: 	unless (&allowed('ccr',$url)) {
 1289:            &logthis('Refused custom assignrole: '.
 1290:              $udom.' '.$uname.' '.$url.' '.$role.' '.$end.' '.$start.' by '.
 1291: 		    $ENV{'user.name'}.' at '.$ENV{'user.domain'});
 1292:            return 'refused'; 
 1293:         }
 1294:         $mrole='cr';
 1295:     } else {
 1296:         my $cwosec=$url;
 1297:         $cwosec=~s/^\/(\w+)\/(\w+)\/.*/$1\/$2/;
 1298:         unless (&allowed('c'.$role,$cwosec)) { 
 1299:            &logthis('Refused assignrole: '.
 1300:              $udom.' '.$uname.' '.$url.' '.$role.' '.$end.' '.$start.' by '.
 1301: 		    $ENV{'user.name'}.' at '.$ENV{'user.domain'});
 1302:            return 'refused'; 
 1303:         }
 1304:         $mrole=$role;
 1305:     }
 1306:     my $command="encrypt:rolesput:$ENV{'user.domain'}:$ENV{'user.name'}:".
 1307:                 "$udom:$uname:$url".'_'."$mrole=$role";
 1308:     if ($end) { $command.='_'.$end; }
 1309:     if ($start) {
 1310: 	if ($end) { 
 1311:            $command.='_'.$start; 
 1312:         } else {
 1313:            $command.='_0_'.$start;
 1314:         }
 1315:     }
 1316:     return &reply($command,&homeserver($uname,$udom));
 1317: }
 1318: 
 1319: # --------------------------------------------------------------- Modify a user
 1320: 
 1321: 
 1322: sub modifyuser {
 1323:     my ($udom,$uname,$uid,$umode,$upass,$first,$middle,$last,$gene)=@_;
 1324:     &logthis('Call to modify user '.$udom.', '.$uname.', '.$uid.', '.
 1325:              $umode.', '.$first.', '.$middle.', '.
 1326: 	     $last.', '.$gene.' by '.
 1327:              $ENV{'user.name'}.' at '.$ENV{'user.domain'});  
 1328:     my $uhome=&homeserver($uname,$udom);
 1329: # ----------------------------------------------------------------- Create User
 1330:     if (($uhome eq 'no_host') && ($umode) && ($upass)) {
 1331:         my $unhome='';
 1332: 	if ($ENV{'course.'.$ENV{'request.course.id'}.'.domain'} eq $udom) {
 1333: 	    $unhome=$ENV{'course.'.$ENV{'request.course.id'}.'.home'};
 1334:         } else {
 1335:             my $tryserver;
 1336:             my $loadm=10000000;
 1337:             foreach $tryserver (keys %libserv) {
 1338: 	       if ($hostdom{$tryserver} eq $udom) {
 1339:                   my $answer=reply('load',$tryserver);
 1340:                   if (($answer=~/\d+/) && ($answer<$loadm)) {
 1341: 		      $loadm=$answer;
 1342:                       $unhome=$tryserver;
 1343:                   }
 1344: 	       }
 1345: 	    }
 1346:         }
 1347:         if (($unhome eq '') || ($unhome eq 'no_host')) {
 1348: 	    return 'error: find home';
 1349:         }
 1350:         my $reply=&reply('encrypt:makeuser:'.$udom.':'.$uname.':'.$umode.':'.
 1351:                          &escape($upass),$unhome);
 1352: 	unless ($reply eq 'ok') {
 1353:             return 'error: '.$reply;
 1354:         }   
 1355:         $uhome=&homeserver($uname,$udom);
 1356:         if (($uhome eq '') || ($uhome eq 'no_host') || ($uhome ne $unhome)) {
 1357: 	    return 'error: verify home';
 1358:         }
 1359:     }
 1360: # ---------------------------------------------------------------------- Add ID
 1361:     if ($uid) {
 1362:        $uid=~tr/A-Z/a-z/;
 1363:        my %uidhash=&idrget($udom,$uname);
 1364:        if (($uidhash{$uname}) && ($uidhash{$uname}!~/error\:/)) {
 1365: 	  unless ($uid eq $uidhash{$uname}) {
 1366: 	      return 'error: mismatch '.$uidhash{$uname}.' versus '.$uid;
 1367:           }
 1368:        } else {
 1369: 	  &idput($udom,($uname => $uid));
 1370:        }
 1371:     }
 1372: # -------------------------------------------------------------- Add names, etc
 1373:     my $names=&reply('get:'.$udom.':'.$uname.
 1374:                      ':environment:firstname&middlename&lastname&generation',
 1375:                      $uhome);
 1376:     my ($efirst,$emiddle,$elast,$egene)=split(/\&/,$names);
 1377:     if ($first)  { $efirst  = &escape($first); }
 1378:     if ($middle) { $emiddle = &escape($middle); }
 1379:     if ($last)   { $elast   = &escape($last); }
 1380:     if ($gene)   { $egene   = &escape($gene); }
 1381:     my $reply=&reply('put:'.$udom.':'.$uname.
 1382:            ':environment:firstname='.$efirst.
 1383:                       '&middlename='.$emiddle.
 1384:                         '&lastname='.$elast.
 1385:                       '&generation='.$egene,$uhome);
 1386:     if ($reply ne 'ok') {
 1387: 	return 'error: '.$reply;
 1388:     }
 1389:     &logthis('Success modifying user '.$udom.', '.$uname.', '.$uid.', '.
 1390:              $umode.', '.$first.', '.$middle.', '.
 1391: 	     $last.', '.$gene.' by '.
 1392:              $ENV{'user.name'}.' at '.$ENV{'user.domain'});
 1393:     return 'ok'; 
 1394: }
 1395: 
 1396: # -------------------------------------------------------------- Modify student
 1397: 
 1398: sub modifystudent {
 1399:     my ($udom,$uname,$uid,$umode,$upass,$first,$middle,$last,$gene,$usec,
 1400:         $end,$start)=@_;
 1401:     my $cid='';
 1402:     unless ($cid=$ENV{'request.course.id'}) {
 1403: 	return 'not_in_class';
 1404:     }
 1405: # --------------------------------------------------------------- Make the user
 1406:     my $reply=&modifyuser
 1407: 	($udom,$uname,$uid,$umode,$upass,$first,$middle,$last,$gene);
 1408:     unless ($reply eq 'ok') { return $reply; }
 1409:     my $uhome=&homeserver($uname,$udom);
 1410:     if (($uhome eq '') || ($uhome eq 'no_host')) { 
 1411: 	return 'error: no such user';
 1412:     }
 1413: # -------------------------------------------------- Add student to course list
 1414:     my $reply=critical('put:'.$ENV{'course.'.$cid.'.domain'}.':'.
 1415: 	              $ENV{'course.'.$cid.'.num'}.':classlist:'.
 1416:                       &escape($uname.':'.$udom).'='.
 1417:                       &escape($end.':'.$start),
 1418: 	              $ENV{'course.'.$cid.'.home'});
 1419:     unless (($reply eq 'ok') || ($reply eq 'delayed')) {
 1420: 	return 'error: '.$reply;
 1421:     }
 1422: # ---------------------------------------------------- Add student role to user
 1423:     my $uurl='/'.$cid;
 1424:     $uurl=~s/\_/\//g;
 1425:     if ($usec) {
 1426: 	$uurl.='/'.$usec;
 1427:     }
 1428:     return &assignrole($udom,$uname,$uurl,'st',$end,$start);
 1429: }
 1430: 
 1431: # ------------------------------------------------- Write to course preferences
 1432: 
 1433: sub writecoursepref {
 1434:     my ($courseid,%prefs)=@_;
 1435:     $courseid=~s/^\///;
 1436:     $courseid=~s/\_/\//g;
 1437:     my ($cdomain,$cnum)=split(/\//,$courseid);
 1438:     my $chome=homeserver($cnum,$cdomain);
 1439:     if (($chome eq '') || ($chome eq 'no_host')) { 
 1440: 	return 'error: no such course';
 1441:     }
 1442:     my $cstring='';
 1443:     map {
 1444: 	$cstring.=escape($_).'='.escape($prefs{$_}).'&';
 1445:     } keys %prefs;
 1446:     $cstring=~s/\&$//;
 1447:     return reply('put:'.$cdomain.':'.$cnum.':environment:'.$cstring,$chome);
 1448: }
 1449: 
 1450: # ---------------------------------------------------------- Make/modify course
 1451: 
 1452: sub createcourse {
 1453:     my ($udom,$description,$url)=@_;
 1454:     $url=&declutter($url);
 1455:     my $cid='';
 1456:     unless (&allowed('ccc',$ENV{'user.domain'})) {
 1457:         return 'refused';
 1458:     }
 1459:     unless ($udom eq $ENV{'user.domain'}) {
 1460:         return 'refused';
 1461:     }
 1462: # ------------------------------------------------------------------- Create ID
 1463:    my $uname=substr($$.time,0,5).unpack("H8",pack("I32",time)).
 1464:        unpack("H2",pack("I32",int(rand(255)))).$perlvar{'lonHostID'};
 1465: # ----------------------------------------------- Make sure that does not exist
 1466:    my $uhome=&homeserver($uname,$udom);
 1467:    unless (($uhome eq '') || ($uhome eq 'no_host')) {
 1468:        $uname=substr($$.time,0,5).unpack("H8",pack("I32",time)).
 1469:         unpack("H2",pack("I32",int(rand(255)))).$perlvar{'lonHostID'};
 1470:        $uhome=&homeserver($uname,$udom);       
 1471:        unless (($uhome eq '') || ($uhome eq 'no_host')) {
 1472:            return 'error: unable to generate unique course-ID';
 1473:        } 
 1474:    }
 1475: # ------------------------------------------------------------- Make the course
 1476:     my $reply=&reply('encrypt:makeuser:'.$udom.':'.$uname.':none::',
 1477:                       $ENV{'user.home'});
 1478:     unless ($reply eq 'ok') { return 'error: '.$reply; }
 1479:     my $uhome=&homeserver($uname,$udom);
 1480:     if (($uhome eq '') || ($uhome eq 'no_host')) { 
 1481: 	return 'error: no such course';
 1482:     }
 1483:     &writecoursepref($udom.'_'.$uname,
 1484:                      ('description' => $description,
 1485:                       'url'         => $url));
 1486:     return '/'.$udom.'/'.$uname;
 1487: }
 1488: 
 1489: # ---------------------------------------------------------- Assign Custom Role
 1490: 
 1491: sub assigncustomrole {
 1492:     my ($udom,$uname,$url,$rdom,$rnam,$rolename,$end,$start)=@_;
 1493:     return &assignrole($udom,$uname,$url,'cr/'.$rdom.'/'.$rnam.'/'.$rolename,
 1494:                        $end,$start);
 1495: }
 1496: 
 1497: # ----------------------------------------------------------------- Revoke Role
 1498: 
 1499: sub revokerole {
 1500:     my ($udom,$uname,$url,$role)=@_;
 1501:     my $now=time;
 1502:     return &assignrole($udom,$uname,$url,$role,$now);
 1503: }
 1504: 
 1505: # ---------------------------------------------------------- Revoke Custom Role
 1506: 
 1507: sub revokecustomrole {
 1508:     my ($udom,$uname,$url,$rdom,$rnam,$rolename)=@_;
 1509:     my $now=time;
 1510:     return &assigncustomrole($udom,$uname,$url,$rdom,$rnam,$rolename,$now);
 1511: }
 1512: 
 1513: # ------------------------------------------------------------ Directory lister
 1514: 
 1515: sub dirlist {
 1516:     my $uri=shift;
 1517:     $uri=~s/^\///;
 1518:     $uri=~s/\/$//;
 1519:     my ($res,$udom,$uname,@rest)=split(/\//,$uri);
 1520:     if ($udom) {
 1521:      if ($uname) {
 1522:        my $listing=reply('ls:'.$perlvar{'lonDocRoot'}.'/'.$uri,
 1523:                       homeserver($uname,$udom));
 1524:        return split(/:/,$listing);
 1525:      } else {
 1526:        my $tryserver;
 1527:        my %allusers=();
 1528:        foreach $tryserver (keys %libserv) {
 1529: 	  if ($hostdom{$tryserver} eq $udom) {
 1530:              my $listing=reply('ls:'.$perlvar{'lonDocRoot'}.'/res/'.$udom,
 1531: 			       $tryserver);
 1532:              if (($listing ne 'no_such_dir') && ($listing ne 'empty')
 1533:               && ($listing ne 'con_lost')) {
 1534:                 map {
 1535:                   my ($entry,@stat)=split(/&/,$_);
 1536:                   $allusers{$entry}=1;
 1537:                 } split(/:/,$listing);
 1538:              }
 1539: 	  }
 1540:        }
 1541:        my $alluserstr='';
 1542:        map {
 1543:            $alluserstr.=$_.'&user:';
 1544:        } sort keys %allusers;
 1545:        $alluserstr=~s/:$//;
 1546:        return split(/:/,$alluserstr);
 1547:      } 
 1548:    } else {
 1549:        my $tryserver;
 1550:        my %alldom=();
 1551:        foreach $tryserver (keys %libserv) {
 1552: 	   $alldom{$hostdom{$tryserver}}=1;
 1553:        }
 1554:        my $alldomstr='';
 1555:        map {
 1556:           $alldomstr.=$perlvar{'lonDocRoot'}.'/res/'.$_.'&domain:';
 1557:        } sort keys %alldom;
 1558:        $alldomstr=~s/:$//;
 1559:        return split(/:/,$alldomstr);       
 1560:    }
 1561: }
 1562: 
 1563: # -------------------------------------------------------- Value of a Condition
 1564: 
 1565: sub directcondval {
 1566:     my $number=shift;
 1567:     if ($ENV{'user.state.'.$ENV{'request.course.id'}}) {
 1568:        return substr($ENV{'user.state.'.$ENV{'request.course.id'}},$number,1);
 1569:     } else {
 1570:        return 2;
 1571:     }
 1572: }
 1573: 
 1574: sub condval {
 1575:     my $condidx=shift;
 1576:     my $result=0;
 1577:     my $allpathcond='';
 1578:     map {
 1579:        if (defined($ENV{'acc.cond.'.$ENV{'request.course.id'}.'.'.$_})) {
 1580: 	   $allpathcond.=
 1581:                '('.$ENV{'acc.cond.'.$ENV{'request.course.id'}.'.'.$_}.')|';
 1582:        }
 1583:     } split(/\|/,$condidx);
 1584:     $allpathcond=~s/\|$//;
 1585:     if ($ENV{'request.course.id'}) {
 1586:        if ($allpathcond) {
 1587:           my $operand='|';
 1588: 	  my @stack;
 1589:           map {
 1590:               if ($_ eq '(') {
 1591:                  push @stack,($operand,$result)
 1592:               } elsif ($_ eq ')') {
 1593:                   my $before=pop @stack;
 1594: 		  if (pop @stack eq '&') {
 1595: 		      $result=$result>$before?$before:$result;
 1596:                   } else {
 1597:                       $result=$result>$before?$result:$before;
 1598:                   }
 1599:               } elsif (($_ eq '&') || ($_ eq '|')) {
 1600:                   $operand=$_;
 1601:               } else {
 1602:                   my $new=directcondval($_);
 1603:                   if ($operand eq '&') {
 1604:                      $result=$result>$new?$new:$result;
 1605:                   } else {
 1606:                      $result=$result>$new?$result:$new;
 1607:                   }                  
 1608:               }
 1609:           } ($allpathcond=~/(\d+|\(|\)|\&|\|)/g);
 1610:        }
 1611:     }
 1612:     return $result;
 1613: }
 1614: 
 1615: # --------------------------------------------------------- Value of a Variable
 1616: 
 1617: sub EXT {
 1618:     my $varname=shift;
 1619:     unless ($varname) { return ''; }
 1620:     my ($realm,$space,$qualifier,@therest)=split(/\./,$varname);
 1621:     my $rest;
 1622:     if ($therest[0]) {
 1623:        $rest=join('.',@therest);
 1624:     } else {
 1625:        $rest='';
 1626:     }
 1627:     my $qualifierrest=$qualifier;
 1628:     if ($rest) { $qualifierrest.='.'.$rest; }
 1629:     my $spacequalifierrest=$space;
 1630:     if ($qualifierrest) { $spacequalifierrest.='.'.$qualifierrest; }
 1631:     if ($realm eq 'user') {
 1632: # --------------------------------------------------------------- user.resource
 1633: 	if ($space eq 'resource') {
 1634: 	    my %restored=&restore;
 1635:             return $restored{$qualifierrest};
 1636: # ----------------------------------------------------------------- user.access
 1637:         } elsif ($space eq 'access') {
 1638:             return &allowed($qualifier,$rest);
 1639: # ------------------------------------------ user.preferences, user.environment
 1640:         } elsif (($space eq 'preferences') || ($space eq 'environment')) {
 1641:             return $ENV{join('.',('environment',$qualifierrest))};
 1642: # ----------------------------------------------------------------- user.course
 1643:         } elsif ($space eq 'course') {
 1644:             return $ENV{join('.',('request.course',$qualifier))};
 1645: # ------------------------------------------------------------------- user.role
 1646:         } elsif ($space eq 'role') {
 1647:             my ($role,$where)=split(/\./,$ENV{'request.role'});
 1648:             if ($qualifier eq 'value') {
 1649: 		return $role;
 1650:             } elsif ($qualifier eq 'extent') {
 1651:                 return $where;
 1652:             }
 1653: # ----------------------------------------------------------------- user.domain
 1654:         } elsif ($space eq 'domain') {
 1655:             return $ENV{'user.domain'};
 1656: # ------------------------------------------------------------------- user.name
 1657:         } elsif ($space eq 'name') {
 1658:             return $ENV{'user.name'};
 1659: # ---------------------------------------------------- Any other user namespace
 1660:         } else {
 1661:             my $item=($rest)?$qualifier.'.'.$rest:$qualifier;
 1662:             my %reply=&get($space,$item);
 1663:             return $reply{$item};
 1664:         }
 1665:     } elsif ($realm eq 'request') {
 1666: # ------------------------------------------------------------- request.browser
 1667:         if ($space eq 'browser') {
 1668: 	    return $ENV{'browser.'.$qualifier};
 1669: # ------------------------------------------------------------ request.filename
 1670:         } else {
 1671:             return $ENV{'request.'.$spacequalifierrest};
 1672:         }
 1673:     } elsif ($realm eq 'course') {
 1674: # ---------------------------------------------------------- course.description
 1675:         my $section='';
 1676:         if ($ENV{'request.course.sec'}) {
 1677: 	    $section='_'.$ENV{'request.course.sec'};
 1678:         }
 1679:         return $ENV{'course.'.$ENV{'request.course.id'}.$section.'.'.
 1680:                               $spacequalifierrest};
 1681:     } elsif ($realm eq 'resource') {
 1682:       if ($ENV{'request.course.id'}) {
 1683: # ----------------------------------------------------- Cascading lookup scheme
 1684:        my $symbp=&symbread();
 1685:        my $mapp=(split(/\_\_\_/,$symbp))[0];
 1686: 
 1687:        my $symbparm=$symbp.'.'.$spacequalifierrest;
 1688:        my $mapparm=$mapp.'___(all).'.$spacequalifierrest;
 1689: 
 1690:        my $seclevel=
 1691:             $ENV{'request.course.id'}.'.['.
 1692: 		$ENV{'request.course.sec'}.'].'.$spacequalifierrest;
 1693:        my $seclevelr=
 1694:             $ENV{'request.course.id'}.'.['.
 1695: 		$ENV{'request.course.sec'}.'].'.$symbparm;
 1696:        my $seclevelm=
 1697:             $ENV{'request.course.id'}.'.['.
 1698: 		$ENV{'request.course.sec'}.'].'.$mapparm;
 1699: 
 1700:        my $courselevel=
 1701:             $ENV{'request.course.id'}.'.'.$spacequalifierrest;
 1702:        my $courselevelr=
 1703:             $ENV{'request.course.id'}.'.'.$symbparm;
 1704:        my $courselevelm=
 1705:             $ENV{'request.course.id'}.'.'.$mapparm;
 1706: 
 1707: # ----------------------------------------------------------- first, check user
 1708:       my %resourcedata=get('resourcedata',
 1709:                            ($courselevelr,$courselevelm,$courselevel));
 1710:       if (($resourcedata{$courselevelr}!~/^error\:/) &&
 1711:           ($resourcedata{$courselevelr}!~/^con_lost/)) {
 1712: 
 1713:        if ($resourcedata{$courselevelr}) { 
 1714:           return $resourcedata{$courselevelr}; }
 1715:        if ($resourcedata{$courselevelm}) { 
 1716:           return $resourcedata{$courselevelm}; }
 1717:        if ($resourcedata{$courselevel}) { return $resourcedata{$courselevel}; }
 1718: 
 1719:       } else {
 1720: 	  if ($resourcedata{$courselevelr}!~/No such file/) {
 1721: 	    &logthis("<font color=blue>WARNING:".
 1722: 		   " Trying to get resource data for ".$ENV{'user.name'}." at "
 1723:                    .$ENV{'user.domain'}.": ".$resourcedata{$courselevelr}.
 1724:                  "</font>");
 1725: 	  }
 1726:       }
 1727: 
 1728: # -------------------------------------------------------- second, check course
 1729: 
 1730:         my $reply=&reply('get:'.
 1731:               $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
 1732:               $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.
 1733: 	      ':resourcedata:'.
 1734:    &escape($seclevelr).'&'.&escape($seclevelm).'&'.&escape($seclevel).'&'.
 1735:    &escape($courselevelr).'&'.&escape($courselevelm).'&'.&escape($courselevel),
 1736: 		   $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
 1737:       if ($reply!~/^error\:/) {
 1738: 	  map {
 1739: 	      if ($_) { return &unescape($_); }
 1740:           } split(/\&/,$reply);
 1741:       }
 1742:       if (($reply=~/^con_lost/) || ($reply=~/^error\:/)) {
 1743: 	  &logthis("<font color=blue>WARNING:".
 1744:                 " Getting ".$reply." asking for ".$varname." for ".
 1745:                 $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.
 1746:                 ' at '.
 1747:                 $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.
 1748:                 ' from '.
 1749:                 $ENV{'course.'.$ENV{'request.course.id'}.'.home'}.
 1750:                  "</font>");
 1751:       }
 1752: # ------------------------------------------------------ third, check map parms
 1753:        my %parmhash=();
 1754:        my $thisparm='';       
 1755:        if (tie(%parmhash,'GDBM_File',
 1756:           $ENV{'request.course.fn'}.'_parms.db',&GDBM_READER,0640)) {
 1757:            $thisparm=$parmhash{$symbparm};
 1758: 	   untie(%parmhash);
 1759:        }
 1760:        if ($thisparm) { return $thisparm; }
 1761:      }
 1762:      
 1763: # --------------------------------------------- last, look in resource metadata
 1764: 
 1765:       $spacequalifierrest=~s/\./\_/;
 1766:       my $metadata=&metadata($ENV{'request.filename'},$spacequalifierrest);
 1767:       if ($metadata) { return $metadata; }
 1768:       $metadata=&metadata($ENV{'request.filename'},
 1769:                                          'parameter_'.$spacequalifierrest);
 1770:       if ($metadata) { return $metadata; }
 1771: 
 1772: # ---------------------------------------------------- Any other user namespace
 1773:     } elsif ($realm eq 'environment') {
 1774: # ----------------------------------------------------------------- environment
 1775:         return $ENV{$spacequalifierrest};
 1776:     } elsif ($realm eq 'system') {
 1777: # ----------------------------------------------------------------- system.time
 1778: 	if ($space eq 'time') {
 1779: 	    return time;
 1780:         }
 1781:     }
 1782:     return '';
 1783: }
 1784: 
 1785: # ---------------------------------------------------------------- Get metadata
 1786: 
 1787: sub metadata {
 1788:     my ($uri,$what)=@_;
 1789: 
 1790:     $uri=&declutter($uri);
 1791:     my $filename=$uri;
 1792:     $uri=~s/\.meta$//;
 1793:     unless ($metacache{$uri.':keys'}) {
 1794:         unless ($filename=~/\.meta$/) { $filename.='.meta'; }
 1795: 	my $metastring=&getfile($perlvar{'lonDocRoot'}.'/res/'.$filename);
 1796:         my $parser=HTML::TokeParser->new(\$metastring);
 1797:         my $token;
 1798:         while ($token=$parser->get_token) {
 1799:            if ($token->[0] eq 'S') {
 1800: 	      my $entry=$token->[1];
 1801:               my $unikey=$entry;
 1802:               if (defined($token->[2]->{'part'})) { 
 1803:                  $unikey.='_'.$token->[2]->{'part'}; 
 1804: 	      }
 1805:               if (defined($token->[2]->{'name'})) { 
 1806:                  $unikey.='_'.$token->[2]->{'name'}; 
 1807: 	      }
 1808:               if ($metacache{$uri.':keys'}) {
 1809:                  $metacache{$uri.':keys'}.=','.$unikey;
 1810:               } else {
 1811:                  $metacache{$uri.':keys'}=$unikey;
 1812: 	      }
 1813:               map {
 1814: 		  $metacache{$uri.':'.$unikey.'.'.$_}=$token->[2]->{$_};
 1815:               } @{$token->[3]};
 1816:               unless (
 1817:                  $metacache{$uri.':'.$unikey}=$parser->get_text('/'.$entry)
 1818: 		      ) { $metacache{$uri.':'.$unikey}=
 1819: 			      $metacache{$uri.':'.$unikey.'.default'};
 1820: 		      }
 1821:           }
 1822:        }
 1823:     }
 1824:     return $metacache{$uri.':'.$what};
 1825: }
 1826: 
 1827: # ------------------------------------------------- Update symbolic store links
 1828: 
 1829: sub symblist {
 1830:     my ($mapname,%newhash)=@_;
 1831:     $mapname=declutter($mapname);
 1832:     my %hash;
 1833:     if (($ENV{'request.course.fn'}) && (%newhash)) {
 1834:         if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
 1835:                       &GDBM_WRCREAT,0640)) {
 1836: 	    map {
 1837:                 $hash{declutter($_)}=$mapname.'___'.$newhash{$_};
 1838:             } keys %newhash;
 1839:             if (untie(%hash)) {
 1840: 		return 'ok';
 1841:             }
 1842:         }
 1843:     }
 1844:     return 'error';
 1845: }
 1846: 
 1847: # ------------------------------------------------------ Return symb list entry
 1848: 
 1849: sub symbread {
 1850:     my $thisfn=shift;
 1851:     unless ($thisfn) {
 1852: 	$thisfn=$ENV{'request.filename'};
 1853:     }
 1854:     $thisfn=declutter($thisfn);
 1855:     my %hash;
 1856:     my %bighash;
 1857:     my $syval='';
 1858:     if (($ENV{'request.course.fn'}) && ($thisfn)) {
 1859:         if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
 1860:                       &GDBM_READER,0640)) {
 1861: 	    $syval=$hash{$thisfn};
 1862:             untie(%hash);
 1863:         }
 1864: # ---------------------------------------------------------- There was an entry
 1865:         if ($syval) {
 1866:            unless ($syval=~/\_\d+$/) {
 1867: 	       unless ($ENV{'form.request.prefix'}=~/\.(\d+)\_$/) {
 1868:                   &appenv('request.ambiguous' => $thisfn);
 1869:                   return '';
 1870:                }    
 1871:                $syval.=$1;
 1872: 	   }
 1873:         } else {
 1874: # ------------------------------------------------------- Was not in symb table
 1875:            if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
 1876:                             &GDBM_READER,0640)) {
 1877: # ---------------------------------------------- Get ID(s) for current resource
 1878:               my $ids=$bighash{'ids_/res/'.$thisfn};
 1879:               unless ($ids) { 
 1880:                  $ids=$bighash{'ids_/'.$thisfn};
 1881:               }
 1882:               if ($ids) {
 1883: # ------------------------------------------------------------------- Has ID(s)
 1884:                  my @possibilities=split(/\,/,$ids);
 1885:                  if ($#possibilities==0) {
 1886: # ----------------------------------------------- There is only one possibility
 1887: 		     my ($mapid,$resid)=split(/\./,$ids);
 1888:                      $syval=declutter($bighash{'map_id_'.$mapid}).'___'.$resid;
 1889:                  } else {
 1890: # ------------------------------------------ There is more than one possibility
 1891:                      my $realpossible=0;
 1892:                      map {
 1893: 			 my $file=$bighash{'src_'.$_};
 1894:                          if (&allowed('bre',$file)) {
 1895:          		    my ($mapid,$resid)=split(/\./,$_);
 1896:                             if ($bighash{'map_type_'.$mapid} ne 'page') {
 1897: 				$realpossible++;
 1898:                                 $syval=declutter($bighash{'map_id_'.$mapid}).
 1899:                                        '___'.$resid;
 1900:                             }
 1901: 			 }
 1902:                      } @possibilities;
 1903: 		     if ($realpossible!=1) { $syval=''; }
 1904:                  }
 1905: 	      }
 1906:               untie(%bighash)
 1907:            } 
 1908:         }
 1909:         if ($syval) {
 1910:            return $syval.'___'.$thisfn; 
 1911:         }
 1912:     }
 1913:     &appenv('request.ambiguous' => $thisfn);
 1914:     return '';
 1915: }
 1916: 
 1917: # ---------------------------------------------------------- Return random seed
 1918: 
 1919: sub numval {
 1920:     my $txt=shift;
 1921:     $txt=~tr/A-J/0-9/;
 1922:     $txt=~tr/a-j/0-9/;
 1923:     $txt=~tr/K-T/0-9/;
 1924:     $txt=~tr/k-t/0-9/;
 1925:     $txt=~tr/U-Z/0-5/;
 1926:     $txt=~tr/u-z/0-5/;
 1927:     $txt=~s/\D//g;
 1928:     return int($txt);
 1929: }    
 1930: 
 1931: sub rndseed {
 1932:     my $symb;
 1933:     unless ($symb=&symbread()) { return time; }
 1934:     { 
 1935:       use integer;
 1936:       my $symbchck=unpack("%32C*",$symb) << 27;
 1937:       my $symbseed=numval($symb) << 22;
 1938:       my $namechck=unpack("%32C*",$ENV{'user.name'}) << 17;
 1939:       my $nameseed=numval($ENV{'user.name'}) << 12;
 1940:       my $domainseed=unpack("%32C*",$ENV{'user.domain'}) << 7;
 1941:       my $courseseed=unpack("%32C*",$ENV{'request.course.id'});
 1942:       my $num=$symbseed+$nameseed+$domainseed+$courseseed+$namechck+$symbchck;
 1943:       #uncommenting these lines can break things!
 1944:       #&Apache::lonxml::debug("$symbseed:$nameseed;$domainseed|$courseseed;$namechck:$symbchck");
 1945:       #&Apache::lonxml::debug("rndseed :$num:$symb");
 1946:       return $num;
 1947:     }
 1948: }
 1949: 
 1950: sub ireceipt {
 1951:     my ($funame,$fudom,$fucourseid,$fusymb)=@_;
 1952:     my $cuname=unpack("%32C*",$funame);
 1953:     my $cudom=unpack("%32C*",$fudom);
 1954:     my $cucourseid=unpack("%32C*",$fucourseid);
 1955:     my $cusymb=unpack("%32C*",$fusymb);
 1956:     my $cunique=unpack("%32C*",$perlvar{'lonReceipt'});
 1957:     return unpack("%32C*",$perlvar{'lonHostID'}).'-'.
 1958:            ($cunique%$cuname+
 1959:             $cunique%$cudom+
 1960:             $cusymb%$cuname+
 1961:             $cusymb%$cudom+
 1962:             $cucourseid%$cuname+
 1963:             $cucourseid%$cudom);
 1964: }
 1965: 
 1966: sub receipt {
 1967:     return &ireceipt($ENV{'user.name'},$ENV{'user.domain'},
 1968:                      $ENV{'request.course.id'},&symbread());
 1969: }
 1970:   
 1971: # ------------------------------------------------------------ Serves up a file
 1972: # returns either the contents of the file or a -1
 1973: sub getfile {
 1974:   my $file=shift;
 1975:   &repcopy($file);
 1976:   if (! -e $file ) { return -1; };
 1977:   my $fh=Apache::File->new($file);
 1978:   my $a='';
 1979:   while (<$fh>) { $a .=$_; }
 1980:   return $a
 1981: }
 1982: 
 1983: sub filelocation {
 1984:   my ($dir,$file) = @_;
 1985:   my $location;
 1986:   $file=~ s/^\s*(\S+)\s*$/$1/; ## strip off leading and trailing spaces
 1987:   if ($file=~m:^/~:) { # is a contruction space reference
 1988:     $location = $file;
 1989:     $location =~ s:/~(.*?)/(.*):/home/$1/public_html/$2:;
 1990:   } else {
 1991:     $file=~s/^$perlvar{'lonDocRoot'}//;
 1992:     $file=~s:^/*res::;
 1993:     if ( !( $file =~ m:^/:) ) {
 1994:       $location = $dir. '/'.$file;
 1995:     } else {
 1996:       $location = '/home/httpd/html/res'.$file;
 1997:     }
 1998:   }
 1999:   $location=~s://+:/:g; # remove duplicate /
 2000:   while ($location=~m:/\.\./:) {$location=~ s:/[^/]+/\.\./:/:g;} #remove dir/..
 2001:   return $location;
 2002: }
 2003: 
 2004: sub hreflocation {
 2005:     my ($dir,$file)=@_;
 2006:     unless (($_=~/^http:\/\//i) || ($_=~/^\//)) {
 2007:        my $finalpath=filelocation($dir,$file);
 2008:        $finalpath=~s/^\/home\/httpd\/html//;
 2009:        return $finalpath;
 2010:     } else {
 2011:        return $file;
 2012:     }
 2013: }
 2014: 
 2015: # ------------------------------------------------------------- Declutters URLs
 2016: 
 2017: sub declutter {
 2018:     my $thisfn=shift;
 2019:     $thisfn=~s/^$perlvar{'lonDocRoot'}//;
 2020:     $thisfn=~s/^\///;
 2021:     $thisfn=~s/^res\///;
 2022:     return $thisfn;
 2023: }
 2024: 
 2025: # -------------------------------------------------------- Escape Special Chars
 2026: 
 2027: sub escape {
 2028:     my $str=shift;
 2029:     $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
 2030:     return $str;
 2031: }
 2032: 
 2033: # ----------------------------------------------------- Un-Escape Special Chars
 2034: 
 2035: sub unescape {
 2036:     my $str=shift;
 2037:     $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
 2038:     return $str;
 2039: }
 2040: 
 2041: # ================================================================ Main Program
 2042: 
 2043: sub BEGIN {
 2044: if ($readit ne 'done') {
 2045: # ------------------------------------------------------------ Read access.conf
 2046: {
 2047:     my $config=Apache::File->new("/etc/httpd/conf/access.conf");
 2048: 
 2049:     while (my $configline=<$config>) {
 2050:         if ($configline =~ /PerlSetVar/) {
 2051: 	   my ($dummy,$varname,$varvalue)=split(/\s+/,$configline);
 2052:            chomp($varvalue);
 2053:            $perlvar{$varname}=$varvalue;
 2054:         }
 2055:     }
 2056: }
 2057: 
 2058: # ------------------------------------------------------------- Read hosts file
 2059: {
 2060:     my $config=Apache::File->new("$perlvar{'lonTabDir'}/hosts.tab");
 2061: 
 2062:     while (my $configline=<$config>) {
 2063:        my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
 2064:        $hostname{$id}=$name;
 2065:        $hostdom{$id}=$domain;
 2066:        if ($role eq 'library') { $libserv{$id}=$name; }
 2067:     }
 2068: }
 2069: 
 2070: # ------------------------------------------------------ Read spare server file
 2071: {
 2072:     my $config=Apache::File->new("$perlvar{'lonTabDir'}/spare.tab");
 2073: 
 2074:     while (my $configline=<$config>) {
 2075:        chomp($configline);
 2076:        if (($configline) && ($configline ne $perlvar{'lonHostID'})) {
 2077:           $spareid{$configline}=1;
 2078:        }
 2079:     }
 2080: }
 2081: # ------------------------------------------------------------ Read permissions
 2082: {
 2083:     my $config=Apache::File->new("$perlvar{'lonTabDir'}/roles.tab");
 2084: 
 2085:     while (my $configline=<$config>) {
 2086:        chomp($configline);
 2087:        my ($role,$perm)=split(/ /,$configline);
 2088:        if ($perm ne '') { $pr{$role}=$perm; }
 2089:     }
 2090: }
 2091: 
 2092: # -------------------------------------------- Read plain texts for permissions
 2093: {
 2094:     my $config=Apache::File->new("$perlvar{'lonTabDir'}/rolesplain.tab");
 2095: 
 2096:     while (my $configline=<$config>) {
 2097:        chomp($configline);
 2098:        my ($short,$plain)=split(/:/,$configline);
 2099:        if ($plain ne '') { $prp{$short}=$plain; }
 2100:     }
 2101: }
 2102: 
 2103: # ------------------------------------------------------------- Read file types
 2104: {
 2105:     my $config=Apache::File->new("$perlvar{'lonTabDir'}/filetypes.tab");
 2106: 
 2107:     while (my $configline=<$config>) {
 2108:        chomp($configline);
 2109:        my ($ending,$emb,@descr)=split(/\s+/,$configline);
 2110:        if ($descr[0] ne '') { 
 2111:          $fe{$ending}=$emb;
 2112:          $fd{$ending}=join(' ',@descr);
 2113:        }
 2114:     }
 2115: }
 2116: 
 2117: %metacache=();
 2118: 
 2119: $readit='done';
 2120: &logthis('<font color=yellow>INFO: Read configuration</font>');
 2121: }
 2122: }
 2123: 1;

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