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- Added subroutines: check_ipbased_access(), can_view(), missing_cookie_msg(),
  serverstatus_titles(), and get_items() for use in checking access for a
  number of server status scripts in /home/httpd/cgi-bin
- Added localization.
- Updated documentation.

    1: #
    2: # LON-CAPA helpers for cgi-bin scripts
    3: #
    4: # $Id: loncgi.pm,v 1.9 2008/11/28 20:39:43 raeburn 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: 
   31: =pod
   32: 
   33: =head1 NAME
   34: 
   35: loncgi
   36: 
   37: =head1 SYNOPSIS
   38: 
   39: Provides subroutines for checking a LON-CAPA cookie, loading the user's
   40: environment, retrieving arguments passed in via a CGI's Query String,
   41: checking access controls, providing a user with an explanation
   42: when access is denied, and descriptions of various server status pages 
   43: generated by CGI scripts which use these subroutines for authorization.
   44: 
   45: =head1 Subroutines
   46: 
   47: =over 4 
   48: 
   49: =cut
   50: 
   51: #############################################
   52: #############################################
   53: package LONCAPA::loncgi;
   54: 
   55: use strict;
   56: use warnings FATAL=>'all';
   57: no warnings 'uninitialized';
   58: 
   59: use lib '/home/httpd/lib/perl/';
   60: use CGI();
   61: use CGI::Cookie();
   62: use Fcntl qw(:flock);
   63: use LONCAPA;
   64: use LONCAPA::Configuration();
   65: use GDBM_File;
   66: use Apache::lonlocal;
   67: 
   68: my $lonidsdir;
   69: 
   70: BEGIN {
   71:     my $perlvar=LONCAPA::Configuration::read_conf('loncapa.conf');
   72:     delete $perlvar->{'lonReceipt'};
   73:     $lonidsdir = $perlvar->{'lonIDsDir'};
   74: }
   75: 
   76: 
   77: #############################################
   78: #############################################
   79: 
   80: =pod
   81: 
   82: =item check_cookie_and_load_env()
   83: 
   84: Inputs: none
   85: 
   86: Returns: 1 if the user has a LON-CAPA cookie 0 if not.
   87: Loads the users environment into the %env hash if the cookie is correct.
   88: 
   89: =cut
   90: 
   91: #############################################
   92: #############################################
   93: sub check_cookie_and_load_env {
   94:     my %cookies=fetch CGI::Cookie;
   95:     if (exists($cookies{'lonID'}) && 
   96:         -e "$lonidsdir/".$cookies{'lonID'}->value.".id") {
   97:         # cookie found
   98:         &transfer_profile_to_env($cookies{'lonID'}->value);
   99:         return 1;
  100:     } else {
  101:         # No cookie found
  102:         return 0;
  103:     }
  104: }
  105: 
  106: #############################################
  107: #############################################
  108: 
  109: =pod
  110: 
  111: =item check_cookie()
  112: 
  113: Inputs: none
  114: 
  115: Returns: 1 if the user has a LON-CAPA cookie and 0 if not.
  116: 
  117: =cut
  118: 
  119: #############################################
  120: #############################################
  121: sub check_cookie {
  122:     my %cookies=fetch CGI::Cookie;
  123:     if (exists($cookies{'lonID'}) && 
  124:         -e "$lonidsdir/".$cookies{'lonID'}->value.".id") {
  125:         # cookie found
  126:         return 1;
  127:     } else {
  128:         # No cookie found
  129:         return 0;
  130:     }
  131: }
  132: 
  133: #############################################
  134: #############################################
  135: 
  136: =pod
  137: 
  138: =item transfer_profile_to_env()
  139: 
  140: Load the users environment into the %env hash.
  141: 
  142: Inputs: $handle, the name of the users LON-CAPA cookie.
  143: 
  144: Returns: undef
  145: 
  146: =cut
  147: 
  148: #############################################
  149: #############################################
  150: sub transfer_profile_to_env {
  151:     my ($handle)=@_;
  152:    if (tie(my %disk_env,'GDBM_File',"$lonidsdir/$handle.id",&GDBM_READER(),
  153: 	    0640)) {
  154: 	%Apache::lonnet::env = %disk_env;
  155: 	untie(%disk_env);
  156:     }
  157:     $Apache::lonnet::env{'user.environment'} = "$lonidsdir/$handle.id";
  158:     return undef;
  159: }
  160: 
  161: #############################################
  162: #############################################
  163: 
  164: =pod
  165: 
  166: =item check_ipbased_access()
  167: 
  168: Inputs: $page, the identifier of the page to be viewed,
  169:         can be one of the keys in the hash from &serverstatus_titles()
  170: 
  171:         $ip, the IP address of the client requesting the page.
  172: 
  173: Returns: 1 if access is permitted for the requestor's IP.
  174:          Access is allowed if on of the following is true:
  175:          (a) the requestor IP is the loopback address
  176:          (b) Domain configurations for domains hosted on this server include
  177:              the requestor's IP as one of the specified IPs with access
  178:              to this page. (does not apply to 'ping' page type) 
  179: =cut
  180: 
  181: #############################################
  182: #############################################
  183: sub check_ipbased_access {
  184:     my ($page,$ip) = @_;
  185:     my $allowed;
  186:     if (!defined($ip)) {
  187:         $ip = $ENV{'REMOTE_ADDR'};
  188:     }
  189:     if (($page ne 'lonstatus') && ($page ne 'serverstatus')) {
  190:         if ($ip eq '127.0.0.1') {
  191:             $allowed = 1;
  192:             return $allowed;
  193:         }
  194:     }
  195:     if ($page ne 'ping') {
  196:         my @poss_domains = &Apache::lonnet::current_machine_domains();
  197:         foreach my $dom (@poss_domains) {
  198:             my %domconfig = &Apache::lonnet::get_dom('configuration',['serverstatuses'],$dom);
  199:             if (ref($domconfig{'serverstatuses'}) eq 'HASH') {
  200:                 if (ref($domconfig{'serverstatuses'}{$page}) eq 'HASH') {
  201:                     if ($domconfig{'serverstatuses'}{$page}{'machines'} ne '') {
  202:                         my @okmachines = split(/,/,$domconfig{'serverstatuses'}{$page}{'machines'});
  203:                         if (grep(/^\Q$ip\E$/,@okmachines)) {
  204:                             $allowed = 1;
  205:                             last;
  206:                         }
  207:                     }
  208:                 }
  209:             }
  210:         }
  211:     }
  212:     return $allowed;
  213: }
  214: 
  215: #############################################
  216: #############################################
  217: 
  218: =pod
  219: 
  220: =item can_view()
  221: 
  222: Inputs: $page, the identifier of the page to be viewed,
  223:         can be one of the keys in the hash from &serverstatus_titles()
  224: 
  225: Returns: 1 if access to the page is permitted.
  226:          Access allowed if one of the following is true:
  227:          (a) Requestor has LON-CAPA superuser role
  228:          (b) Requestor's role is Domain Coordinator in one of the domains
  229:              hosted on this server
  230:          (c) Domain configurations for domains hosted on this server include
  231:              the requestor as one of the named users (username:domain) with access
  232:              to the page.
  233: 
  234:          In the case of requests for the 'ping' page, and access is also allowed if 
  235:          at least one domain hosted on requestor's server is also hosted on this server.
  236: 
  237: =cut
  238: 
  239: #############################################
  240: #############################################
  241: sub can_view {
  242:     my ($page) = @_;
  243:     my $allowed;
  244:     if ($Apache::lonnet::env{'request.role'} =~ m{^su\./}) {
  245:         $allowed = 1;
  246:     } elsif ($page eq 'ping') {
  247:         my @poss_domains = &Apache::lonnet::current_machine_domains();
  248:         my @hostids= &Apache::lonnet::get_hosts_from_ip($ENV{'REMOTE_ADDR'});
  249:         foreach my $hostid (@hostids) { 
  250:             my $hostdom = &Apache::lonnet::host_domain($hostid);
  251:             if (grep(/^\Q$hostdom\E$/,@poss_domains)) {
  252:                 $allowed = 1;
  253:                 last;
  254:             }
  255:         }
  256:     } else {
  257:         my @poss_domains = &Apache::lonnet::current_machine_domains();
  258:         foreach my $dom (@poss_domains) {
  259:             my %domconfig = &Apache::lonnet::get_dom('configuration',['serverstatuses'],$dom);
  260:             if ($Apache::lonnet::env{'request.role'} eq "dc./$dom/") {
  261:                 $allowed = 1;
  262:             } elsif (ref($domconfig{'serverstatuses'}) eq 'HASH') {
  263:                 if (ref($domconfig{'serverstatuses'}{$page}) eq 'HASH') {
  264:                     if ($domconfig{'serverstatuses'}{$page}{'namedusers'} ne '') {
  265:                         my @okusers = split(/,/,$domconfig{'serverstatuses'}{$page}{'namedusers'});
  266:                         if (grep(/^\Q$Apache::lonnet::env{'user.name'}:$Apache::lonnet::env{'user.domain'}\E$/,@okusers)) {
  267:                             $allowed = 1;
  268:                         }
  269:                     }
  270:                 }
  271:             }
  272:             last if $allowed;
  273:         }
  274:     }
  275:     return $allowed;
  276: }
  277: 
  278: #############################################
  279: #############################################
  280: 
  281: =pod
  282: 
  283: =unauthorized_msg()
  284: 
  285: Inputs: $page, the identifier of the page to be viewed,
  286:         can be one of the keys in the hash from &serverstatus_titles()
  287: 
  288: Returns: A string explaining why access was denied for the particular page.
  289: 
  290: =cut
  291: 
  292: #############################################
  293: #############################################
  294: sub unauthorized_msg {
  295:     my ($page) = @_;
  296:     my $titles = &serverstatus_titles();
  297:     if ($page eq 'clusterstatus') {
  298:         return &mt('Your current role does not permit you to view the requested server status page: [_1]',$titles->{$page});
  299:     }
  300:     my @poss_domains = &Apache::lonnet::current_machine_domains();
  301:     if (@poss_domains == 1) {
  302:         my $domdesc = &Apache::lonnet::domain($poss_domains[0]);
  303:         return &mt('The configuration for domain: [_1] does not permit you to view the requested server status page: [_2].',"$domdesc ($poss_domains[0])",$titles->{$page});
  304:     } elsif (@poss_domains > 1) {
  305:         my $output = &mt('Configurations for the domains housed on this server: ').'<ul>';
  306:         foreach my $dom (@poss_domains) {
  307:             my $domdesc = &Apache::lonnet::domain($dom);
  308:             $output .= '<li>'.&Apache::lonnet::domain($dom).'('.$dom.')</li>';
  309:         }
  310:         $output .= '</ul>'.&mt('do not permit you to view the requested server status page: [_1]',$titles->{$page});
  311:         return $output;
  312:     } else {
  313:         return &mt('No domain information exists for this server');
  314:     }
  315: }
  316: 
  317: #############################################
  318: #############################################
  319: 
  320: =pod
  321: 
  322: =item missing_cookie_msg()
  323: 
  324: Inputs: none
  325: Returns: HTML for a page indicating cookie information absent. 
  326: 
  327: =cut
  328: 
  329: #############################################
  330: #############################################
  331: sub missing_cookie_msg {
  332:     my %lt = &Apache::lonlocal::texthash (
  333:                         cook => 'Bad Cookie',
  334:                         your => 'Your cookie information is incorrect.',
  335:              );
  336:     return <<END;
  337: <html>
  338: <head><title>$lt{'cook'}</title></head>
  339: <body>
  340: $lt{'your'}
  341: </body>
  342: </html>
  343: END
  344: 
  345: }
  346: 
  347: #############################################
  348: #############################################
  349: 
  350: =pod
  351: 
  352: =item serverstatus_titles()
  353: 
  354: Inputs: none
  355: 
  356: Returns: a reference to a hash of pages, where in the hash
  357:          keys are names of pages which employ loncgi.pm
  358:          or lonstatusacc.pm for access control, 
  359:          and corresponding values are descriptions of each page 
  360: 
  361: =cut
  362: 
  363: #############################################
  364: #############################################
  365: sub serverstatus_titles {
  366:     my %titles = &Apache::lonlocal::texthash (
  367:                    'userstatus'        => 'User Status Summary',
  368:                    'lonstatus'         => 'Display Detailed Report',
  369:                    'loncron'           => 'Generate Detailed Report',
  370:                    'server-status'     => 'Apache Status Page',
  371:                    'codeversions'      => 'LON-CAPA Module Versions',
  372:                    'clusterstatus'     => 'Domain status',
  373:                    'metadata_keywords' => 'Display Metadata Keywords',
  374:                    'metadata_harvest'  => 'Harvest Metadata Searches',
  375:                    'takeoffline'       => 'Offline - replace Log-in page',
  376:                    'takeonline'        => 'Online - restore Log-in page',
  377:                    'showenv'           => "Show user environment",
  378:                  );
  379:     return \%titles;
  380: }
  381: 
  382: #############################################
  383: #############################################
  384: 
  385: =pod
  386: 
  387: =cgi_getitems()
  388: 
  389: Inputs: $query (the CGI query string), and $getitems, a reference to a hash 
  390: 
  391: Returns: nothing
  392: 
  393: Side Effects: populates $getitems hash ref with key => value
  394:               where each key is the name of the form item in the query string
  395:               and value is an array of corresponding values. 
  396: =cut
  397: 
  398: #############################################
  399: #############################################
  400: sub cgi_getitems {
  401:     my ($query,$getitems)= @_;
  402:     foreach (split(/&/,$query)) {
  403:         my ($name, $value) = split(/=/,$_);
  404:         $name = &unescape($name);
  405:         $value =~ tr/+/ /;
  406:         $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
  407:         push(@{$$getitems{$name}},$value);
  408:     }
  409:     return;
  410: }
  411: 
  412: =pod
  413: 
  414: =back
  415: 
  416: =cut
  417: 
  418: 1;
  419: 
  420: __END__