File:  [LON-CAPA] / loncom / LONCAPA.pm
Revision 1.24: download - view: text, annotated - select for diffs
Mon Jul 2 21:15:29 2007 UTC (16 years, 9 months ago) by albertel
Branches: MAIN
CVS tags: version_2_8_X, version_2_8_2, version_2_8_1, version_2_8_0, version_2_7_X, version_2_7_99_1, version_2_7_99_0, version_2_7_1, version_2_7_0, version_2_6_X, version_2_6_99_1, version_2_6_99_0, version_2_6_3, version_2_6_2, version_2_6_1, version_2_6_0, version_2_5_X, version_2_5_99_1, version_2_5_99_0, version_2_5_2, version_2_5_1, version_2_5_0, version_2_4_X, version_2_4_99_0, version_2_4_2, HEAD, GCI_1
- BUG#5305 allow @ in usernames

    1: # The LearningOnline Network
    2: # Base routines
    3: #
    4: # $Id: LONCAPA.pm,v 1.24 2007/07/02 21:15:29 albertel Exp $
    5: #
    6: # Copyright Michigan State University Board of Trustees
    7: #
    8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
    9: #
   10: # LON-CAPA is free software; you can redistribute it and/or modify
   11: # it under the terms of the GNU General Public License as published by
   12: # the Free Software Foundation; either version 2 of the License, or
   13: # (at your option) any later version.
   14: #
   15: # LON-CAPA is distributed in the hope that it will be useful,
   16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   18: # GNU General Public License for more details.
   19: #
   20: # You should have received a copy of the GNU General Public License
   21: # along with LON-CAPA; if not, write to the Free Software
   22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   23: #
   24: # /home/httpd/html/adm/gpl.txt
   25: #
   26: # http://www.lon-capa.org/
   27: #
   28: ###
   29: 
   30: package LONCAPA;
   31: 
   32: use strict;
   33: use lib '/home/httpd/lib/perl/';
   34: use LONCAPA::Configuration;
   35: use Fcntl qw(:flock);
   36: use GDBM_File;
   37: use POSIX;
   38: 
   39: my $loncapa_max_wait_time = 13;
   40: 
   41: 
   42: use vars qw($match_domain   $match_not_domain
   43: 	    $match_username $match_not_username
   44: 	    $match_courseid $match_not_courseid
   45: 	    $match_name
   46:             $match_lonid
   47: 	    $match_handle   $match_not_handle);
   48: 
   49: require Exporter;
   50: our @ISA = qw (Exporter);
   51: our @EXPORT = qw(&add_get_param    &escape            &unescape       
   52: 		 &tie_domain_hash  &untie_domain_hash &tie_user_hash
   53: 		 &untie_user_hash  &propath);
   54: our @EXPORT_OK = qw($match_domain   $match_not_domain
   55: 		    $match_username $match_not_username
   56: 		    $match_courseid $match_not_courseid
   57: 		    $match_name
   58: 		    $match_lonid
   59: 		    $match_handle   $match_not_handle);
   60: our %EXPORT_TAGS = ( 'match' =>[qw($match_domain   $match_not_domain
   61: 				   $match_username $match_not_username
   62: 				   $match_courseid $match_not_courseid
   63: 				   $match_name
   64: 				   $match_lonid
   65: 				   $match_handle   $match_not_handle)],);
   66: my %perlvar;
   67: 
   68: 
   69: 
   70: # Inputs are a url, and a hash ref of
   71: # form name => value pairs
   72: # takes care of properly adding the form name elements and values to the 
   73: # the url doing proper escaping of the values and joining with ? or & as 
   74: # needed
   75: 
   76: sub add_get_param {
   77:     my ($url,$form_data) = @_;
   78:     my $needs_question_mark = ($url !~ /\?/);
   79: 
   80:     while (my ($name,$value) = each(%$form_data)) {
   81: 	if ($needs_question_mark) {
   82: 	    $url.='?';
   83: 	    $needs_question_mark = 0;
   84: 	} else { 
   85: 	    $url.='&';
   86: 	}
   87: 	$url.=$name.'='.&escape($form_data->{$name});
   88:     }
   89:     return $url;
   90: }
   91: 
   92: # -------------------------------------------------------- Escape Special Chars
   93: 
   94: sub escape {
   95:     my $str=shift;
   96:     $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
   97:     return $str;
   98: }
   99: 
  100: # ----------------------------------------------------- Un-Escape Special Chars
  101: 
  102: sub unescape {
  103:     my $str=shift;
  104:     $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
  105:     return $str;
  106: }
  107: 
  108: $match_domain     = $LONCAPA::domain_re     = qr{[\w\-.]+};
  109: $match_not_domain = $LONCAPA::not_domain_re = qr{[^\w\-.]+};
  110: sub clean_domain {
  111:     my ($domain) = @_;
  112:     $domain =~ s/$match_not_domain//g;
  113:     return $domain;
  114: }
  115: 
  116: $match_username     = $LONCAPA::username_re     = qr{\w[\w\-.@]+};
  117: $match_not_username = $LONCAPA::not_username_re = qr{[^\w\-.@]+};
  118: sub clean_username {
  119:     my ($username) = @_;
  120:     $username =~ s/^\W+//;
  121:     $username =~ s/$match_not_username//g;
  122:     return $username;
  123: }
  124: 
  125: 
  126: $match_courseid     = $LONCAPA::courseid_re     = qr{\d[\w\-.]+};
  127: $match_not_courseid = $LONCAPA::not_courseid_re = qr{[^\w\-.]+};
  128: sub clean_courseid {
  129:     my ($courseid) = @_;
  130:     $courseid =~ s/^\D+//;
  131:     $courseid =~ s/$match_not_courseid//g;
  132:     return $courseid;
  133: }
  134: 
  135: $match_name         = $LONCAPA::name_re = qr{$match_username|$match_courseid};
  136: sub clean_name {
  137:     my ($name) = @_;
  138:     $name =~ s/$match_not_username//g;
  139:     return $name;
  140: }
  141: 
  142: $match_lonid     = $LONCAPA::lonid_re     = qr{[\w\-.]+};
  143: 
  144: sub split_courseid {
  145:     my ($courseid) = @_;
  146:     my  ($domain,$coursenum) = 
  147: 	($courseid=~m{^/($match_domain)/($match_courseid)});
  148:     return ($domain,$coursenum);
  149: }
  150: 
  151: $match_handle     = $LONCAPA::handle_re     = qr{[\w\-.@]+};
  152: $match_not_handle = $LONCAPA::not_handle_re = qr{[^\w\-.@]+};
  153: sub clean_handle {
  154:     my ($handle) = @_;
  155:     $handle =~ s/$match_not_handle//g;
  156:     return $handle;
  157: }
  158: 
  159: # -------------------------------------------- Return path to profile directory
  160: 
  161: sub propath {
  162:     my ($udom,$uname)=@_;
  163:     $udom = &clean_domain($udom);
  164:     $uname= &clean_name($uname);
  165:     my $subdir=$uname.'__';
  166:     $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
  167:     my $proname="$perlvar{'lonUsersDir'}/$udom/$subdir/$uname";
  168:     return $proname;
  169: } 
  170: 
  171: 
  172: #---------------------------------------------------------------
  173: #
  174: # Manipulation of hash based databases (factoring out common code
  175: # for later use as we refactor.
  176: #
  177: #  Ties a domain level resource file to a hash.
  178: #  If requested a history entry is created in the associated hist file.
  179: #
  180: #  Parameters:
  181: #     domain    - Name of the domain in which the resource file lives.
  182: #     namespace - Name of the hash within that domain.
  183: #     how       - How to tie the hash (e.g. GDBM_WRCREAT()).
  184: #     loghead   - Optional parameter, if present a log entry is created
  185: #                 in the associated history file and this is the first part
  186: #                  of that entry.
  187: #     logtail   - Goes along with loghead,  The actual logentry is of the
  188: #                 form $loghead:<timestamp>:logtail.
  189: # Returns:
  190: #    Reference to a hash bound to the db file or alternatively undef
  191: #    if the tie failed.
  192: #
  193: sub tie_domain_hash {
  194:     my ($domain,$namespace,$how,$loghead,$logtail) = @_;
  195:     
  196:     # Filter out any whitespace in the domain name:
  197:     
  198:     $domain = &clean_domain($domain);
  199:     
  200:     # We have enough to go on to tie the hash:
  201:     
  202:     my $user_top_dir   = $perlvar{'lonUsersDir'};
  203:     my $domain_dir     = $user_top_dir."/$domain";
  204:     my $resource_file  = $domain_dir."/$namespace";
  205:     return &_locking_hash_tie($resource_file,$namespace,$how,$loghead,$logtail);
  206: }
  207: 
  208: sub untie_domain_hash {
  209:     return &_locking_hash_untie(@_);
  210: }
  211: #
  212: #   Ties a user's resource file to a hash.  
  213: #   If necessary, an appropriate history
  214: #   log file entry is made as well.
  215: #   This sub factors out common code from the subs that manipulate
  216: #   the various gdbm files that keep keyword value pairs.
  217: # Parameters:
  218: #   domain       - Name of the domain the user is in.
  219: #   user         - Name of the 'current user'.
  220: #   namespace    - Namespace representing the file to tie.
  221: #   how          - What the tie is done to (e.g. GDBM_WRCREAT().
  222: #   loghead      - Optional first part of log entry if there may be a
  223: #                  history file.
  224: #   what         - Optional tail of log entry if there may be a history
  225: #                  file.
  226: # Returns:
  227: #   hash to which the database is tied.  It's up to the caller to untie.
  228: #   undef if the has could not be tied.
  229: #
  230: sub tie_user_hash {
  231:     my ($domain,$user,$namespace,$how,$loghead,$what) = @_;
  232: 
  233:     $namespace=~s{/}{_}g;	# / -> _
  234:     $namespace     = &clean_username($namespace);
  235:     my $proname    = &propath($domain, $user);
  236:     my $file_prefix="$proname/$namespace";
  237:     return &_locking_hash_tie($file_prefix,$namespace,$how,$loghead,$what);
  238: }
  239: 
  240: sub untie_user_hash {
  241:     return &_locking_hash_untie(@_);
  242: }
  243: 
  244: # routines if you just have a filename
  245: # return tied hashref or undef
  246: 
  247: sub locking_hash_tie {
  248:     my ($filename,$how)=@_;
  249:     my ($file_prefix,$namespace)=&db_filename_parts($filename);
  250:     if ($namespace eq '') { return undef; }
  251:     return &_locking_hash_tie($file_prefix,$namespace,$how);
  252: }
  253: 
  254: sub locking_hash_untie {
  255:     return &_locking_hash_untie(@_);
  256: }
  257: 
  258: sub db_filename_parts {
  259:     my ($filename)=@_;
  260:     my ($file_path,$namespace)=($filename=~/^(.*)\/([^\/]+)\.db$/);
  261:     if ($namespace eq '') { return undef; }
  262:     return ($file_path.'/'.$namespace,$namespace);
  263: }
  264: 
  265: # internal routines that handle the actual tieing and untieing process
  266: 
  267: sub _do_hash_tie {
  268:     my ($file_prefix,$namespace,$how,$loghead,$what) = @_;
  269:     my %hash;
  270:     if(tie(%hash, 'GDBM_File', "$file_prefix.db", $how, 0640)) {
  271: 	# If this is a namespace for which a history is kept,
  272: 	# make the history log entry:    
  273: 	if (($namespace !~/^nohist\_/) && (defined($loghead))) {
  274: 	    my $hfh = IO::File->new(">>$file_prefix.hist"); 
  275: 	    if($hfh) {
  276: 		my $now = time();
  277: 		print $hfh ("$loghead:$now:$what\n");
  278: 	    }
  279: 	    $hfh->close;
  280: 	}
  281: 	return \%hash;
  282:     } else {
  283: 	return undef;
  284:     }
  285: }
  286: 
  287: sub _do_hash_untie {
  288:     my ($hashref) = @_;
  289:     my $result = untie(%$hashref);
  290:     return $result;
  291: }
  292: 
  293: {
  294:     my $sym;
  295:     my @pushed_syms;
  296: 
  297:     sub clean_sym {
  298: 	undef($sym);
  299:     }
  300:     sub push_locking_hash_tie {
  301: 	if (!defined($sym)) {
  302: 	    die("Invalid used of push_locking_hash_tie, should only be called after a lock has occurred and before and unlock.");
  303: 	}
  304: 	push(@pushed_syms,$sym);
  305: 	undef($sym);
  306:     }
  307: 
  308:     sub pop_locking_hash_tie {
  309: 	if (defined($sym)) {
  310: 	    die("Invalid nested used of pop_locking_hash_tie, should only be called after a unlock has occurred.");
  311: 	}
  312: 	$sym = pop(@pushed_syms);
  313:     }
  314: 
  315:     sub _locking_hash_tie {
  316: 	my ($file_prefix,$namespace,$how,$loghead,$what) = @_;
  317: 	if (defined($sym)) {
  318: 	    die('Nested locking attempted without proper use of push_locking_hash_tie, this is unsupported');
  319: 	}
  320: 
  321:         my $lock_type=LOCK_SH;
  322: # Are we reading or writing?
  323:         if ($how eq &GDBM_READER()) {
  324: # We are reading
  325:            if (!open($sym,"$file_prefix.db.lock")) {
  326: # We don't have a lock file. This could mean
  327: # - that there is no such db-file
  328: # - that it does not have a lock file yet
  329:                if ((! -e "$file_prefix.db") && (! -e "$file_prefix.db.gz")) {
  330: # No such file. Forget it.                
  331:                    $! = 2;
  332: 		   &clean_sym();
  333:                    return undef;
  334:                }
  335: # Apparently just no lock file yet. Make one
  336:                open($sym,">>$file_prefix.db.lock");
  337:            }
  338: # Do a shared lock
  339:            if (!&flock_sym(LOCK_SH)) { 
  340: 	       &clean_sym();
  341: 	       return undef; 
  342: 	   } 
  343: # If this is compressed, we will actually need an exclusive lock
  344: 	   if (-e "$file_prefix.db.gz") {
  345: 	       if (!&flock_sym(LOCK_EX)) {
  346: 		   &clean_sym();
  347: 		   return undef;
  348: 	       }
  349: 	   }
  350:         } elsif ($how eq &GDBM_WRCREAT()) {
  351: # We are writing
  352:            open($sym,">>$file_prefix.db.lock");
  353: # Writing needs exclusive lock
  354:            if (!&flock_sym(LOCK_EX)) {
  355: 	       &clean_sym();
  356: 	       return undef;
  357: 	   }
  358:         } else {
  359:            die("Unknown method $how for $file_prefix");
  360:         }
  361: # The file is ours!
  362: # If it is archived, un-archive it now
  363:        if (-e "$file_prefix.db.gz") {
  364:            system("gunzip $file_prefix.db.gz");
  365: 	   if (-e "$file_prefix.hist.gz") {
  366: 	       system("gunzip $file_prefix.hist.gz");
  367: 	   }
  368:        }
  369: # Change access mode to non-blocking
  370:        $how=$how|&GDBM_NOLOCK();
  371: # Go ahead and tie the hash
  372:       	my $result = 
  373: 	    &_do_hash_tie($file_prefix,$namespace,$how,$loghead,$what);
  374: 	if (!$result) {
  375: 	    &clean_sym();
  376: 	}
  377: 	return $result;
  378:     }
  379: 
  380:     sub flock_sym {
  381:         my ($lock_type)=@_;
  382: 	my $failed=0;
  383: 	eval {
  384: 	    local $SIG{__DIE__}='DEFAULT';
  385: 	    local $SIG{ALRM}=sub {
  386: 		$failed=1;
  387: 		die("failed lock");
  388: 	    };
  389: 	    alarm($loncapa_max_wait_time);
  390: 	    flock($sym,$lock_type);
  391: 	    alarm(0);
  392: 	};
  393: 	if ($failed) {
  394: 	    $! = 100; # throwing error # 100
  395: 	    return undef;
  396: 	} else {
  397: 	    return 1;
  398: 	}
  399:     }
  400: 
  401:     sub _locking_hash_untie {
  402: 	my ($hashref) = @_;
  403: 	my $result = untie(%$hashref);
  404: 	flock($sym,LOCK_UN);
  405: 	close($sym);
  406: 	&clean_sym();
  407: 	return $result;
  408:     }
  409: }
  410: 
  411: BEGIN {
  412:     %perlvar=%{&LONCAPA::Configuration::read_conf('loncapa.conf')};
  413: }
  414: 
  415: 1;
  416: 
  417: __END__
  418: 
  419: =pod
  420: 
  421: =head1 NAME
  422: 
  423: LONCAPA - Basic routines
  424: 
  425: =head1 SYNOPSIS
  426: 
  427: Generally useful routines
  428: 
  429: =head1 EXPORTED SUBROUTINES
  430: 
  431: =over 4
  432: 
  433: =item *
  434: 
  435: escape() : unpack non-word characters into CGI-compatible hex codes
  436: 
  437: =item *
  438: 
  439: unescape() : pack CGI-compatible hex codes into actual non-word ASCII character
  440: 
  441: =item *
  442: 
  443: add_get_param() :
  444:  Inputs:  url (with or without exit GET from parameters), hash ref of
  445:               form name => value pairs
  446: 
  447:  Return: url with properly added the form name elements and values to the 
  448:          the url doing proper escaping of the values and joining with ? or &
  449:          as needed
  450: 
  451: =back

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