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- Bug 6034
- Methods checking in webDAV:
  - MKCOL/PUT disallowed for reserved filenames: *.meta, *.bak, *.save, *.log
  - MOVE/DELETE disallowed for published files (unless marked obsolete).
  - MOVE/DELETE disallowed for *.meta and *.log if corresponding file has
    published status (unless marked obsolete).
  - For MOVE/DELETE for a directory do (recursive) count of contained published
    files (unless marked obsolete), and disallow if count > 0.

    1: # The LearningOnline Network
    2: # Authorization Handler for webDAV access to Authoring Space. 
    3: #
    4: # $Id: lonwebdavacc.pm,v 1.2 2014/06/23 20:27:46 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: =pod
   30: 
   31: =head1 NAME
   32: 
   33: Apache::lonwebdavacc - webDAV Authorization Handler
   34: 
   35: =head1 SYNOPSIS
   36: 
   37: Invoked for /+webdav/[\w\-]+/[\w\-]+/ by
   38: /etc/httpd/conf/loncapa_apache.conf:
   39: 
   40: PerlAccessHandler       Apache::lonwebdavacc
   41: 
   42: =head1 INTRODUCTION
   43: 
   44: This module enables authorization for authoring space
   45: and is used to control access for the following type of URI:
   46: 
   47:  <LocationMatch "^/webdav/[\w\-]+/[\w\-]+>
   48: 
   49: This module is only called following successful authentication. 
   50: Unless lonOtherAuthen has been set, so Single Sign On can be used,
   51: successful authentication will have created a session file and
   52: transferred the contents to the user's environment.
   53: 
   54: In the case of SSO, there is no existing user environment, but  
   55: $r->user will have been set to the user's username, following 
   56: successful authentication.  For SSO, the webDAV session file
   57: and environment are set up by a call to 
   58: Apache::lonwebdavauth::init_webdav_env().
   59: 
   60: Note: because Apache Basic Auth is used for authentication (unless SSO)
   61: webDAV access is only available for servers running Apache with SSL.
   62: 
   63: This is part of the LearningOnline Network with CAPA project
   64: described at http://www.lon-capa.org.
   65: 
   66: =head1 HANDLER SUBROUTINE
   67: 
   68: This routine is called by Apache and mod_perl.
   69: 
   70: =over 4
   71: 
   72: =item *
   73: 
   74: Checks if $env{'user.environment'} is defined.
   75: 
   76: =item *
   77: 
   78: If no %env, this was SSO authentication so call to &sso_login() to
   79: create session, and return cookie. 
   80: 
   81: =item *
   82: 
   83: Checks if requested URL (of form /webdav/authordomain/authorname) is valid
   84: and whether authenticated user has an active author or co-author
   85: role in the corresonding Author Space. 
   86: 
   87: =back
   88: 
   89: =head1 NOTABLE SUBROUTINES
   90: 
   91: =over
   92: 
   93: =item * sso_login()
   94: 
   95: =over 
   96: 
   97: =item *
   98: 
   99: Called if no user.environment exists in %env.
  100: 
  101: =item *
  102: 
  103: Checks if $r->user contains a valid user.
  104: 
  105: =item *
  106: 
  107: Domain is set either from lonSSOUserDomain perlvar (if defined)
  108: or from lonDefDomain perlvar.
  109:  
  110: =item *
  111: 
  112: For a valid user a new session file and is created, and the corresponding 
  113: cookie is returned to the client in an Apache response header.
  114: 
  115: =back
  116: 
  117: =back
  118: 
  119: =cut
  120: 
  121: package Apache::lonwebdavacc;
  122: 
  123: use strict;
  124: use GDBM_File;
  125: use Apache::Constants qw(:common :http :methods);
  126: use Apache::lonnet;
  127: use Apache::londiff();
  128: use LONCAPA qw(:DEFAULT :match);
  129: 
  130: sub handler {
  131:     my $r = shift;
  132:     my $timetolive = 600;
  133:     my $now = time;
  134:     my $sessiondir=$r->dir_config('lonDAVsessDir');
  135: 
  136:     my ($adom,$aname);
  137:     unless ($env{'user.environment'}) {
  138:         my $handle = &Apache::lonnet::check_for_valid_session($r,'lonDAV');
  139:         if ($handle eq '') {
  140:             $handle = &sso_login($r,$sessiondir,$now,$timetolive);
  141:             if ($handle eq '') {
  142:                 return FORBIDDEN;
  143:             }
  144:         } else {
  145:             &Apache::lonnet::transfer_profile_to_env($sessiondir,$handle);
  146:         }
  147:     }
  148:     my $uhome=&Apache::lonnet::homeserver($env{'user.name'},$env{'user.domain'});
  149:     if ($uhome =~ /^(con_lost|no_host|no_such_host)$/) {
  150:         return FORBIDDEN;
  151:     }
  152: 
  153:     ($adom,$aname) = ($r->uri =~ m{^/webdav/($match_domain)/($match_username)/});
  154:     my $docroot = $r->dir_config('lonDocRoot');
  155:     if ($adom eq '' || $aname eq '') {
  156:         return FORBIDDEN;
  157:     } elsif (!-d "$docroot/priv/$adom/$aname") {
  158:         return FORBIDDEN;
  159:     }
  160:     my $allowed;  
  161:     if (($env{'user.name'} eq $aname) && ($env{'user.domain'} eq $adom)) {
  162:         if ($env{"user.role.au./$adom/"}) {
  163:             $allowed = 1;
  164:         }
  165:     } else {
  166:         if (($env{"user.role.ca./$adom/$aname"}) ||
  167:             (env{"user.role.aa./$adom/$aname"})) {
  168:             $allowed = 1;
  169:         }
  170:     }
  171:     if ($allowed) {
  172:         my $method = $r->method();
  173:         if (($r->filename =~ /.+\.(log|bak|meta|save)$/) || ($r->filename =~ /\.\d+\.\w+$/) || 
  174:             ($r->filename =~ m{/\.+[^_/]+$})) {
  175:             if (($method eq 'MKCOL') || ($method eq 'PUT')) {
  176:                 return FORBIDDEN;
  177:             } elsif ($method eq 'MOVE') {
  178:                 if (($r->filename =~ /\.\d+\.\w+$/) || ($r->filename =~ m{/\.+[^_/]+$})) {
  179:                     return FORBIDDEN;
  180:                 }
  181:             }
  182:         }
  183:         if (($method eq 'DELETE') || ($method eq 'MOVE')) {
  184:             unless (($r->filename =~ m{/\._[^/]+$}) || ($r->filename =~ m{/\.DS_Store$})) {
  185:                 my $dirptr=16384;
  186:                 my ($cmode,$cmtime)=(stat($r->filename))[2,9];
  187:                 if (($cmode&$dirptr)) {
  188:                     my $numpub = 0;
  189:                     $numpub = &recurse_dir($r->filename,$r->dir_config('lonDocRoot'),$numpub);
  190:                     if ($numpub) {
  191:                         return FORBIDDEN;
  192:                     }
  193:                 } else {
  194:                     if ($r->filename =~ /^(.+)\.(log|bak|save|meta)$/) {
  195:                         my $conjugate = $1;
  196:                         my $type = $2; 
  197:                         if (($type eq 'log') || ($type eq 'meta')) {
  198:                             if (-e $conjugate) {
  199:                                 my $conjstatus = &pubstatus($conjugate,$r->dir_config('lonDocRoot'));
  200:                                 unless (($conjstatus eq 'unpublished') || ($conjstatus eq 'obsolete')) {
  201:                                     return FORBIDDEN;
  202:                                 }
  203:                             }
  204:                         }
  205:                     } else {
  206:                         my $status = &pubstatus($r->filename,$r->dir_config('lonDocRoot'));
  207:                         unless (($status eq 'unpublished') || ($status eq 'obsolete')) {
  208:                             return FORBIDDEN;
  209:                         }
  210:                     }
  211:                 }
  212:             }
  213:         }
  214:         return OK;
  215:     }
  216:     return FORBIDDEN;
  217: }
  218: 
  219: sub sso_login {
  220:     my ($r,$sessiondir,$now,$timetolive) = @_;
  221:     my ($uname,$udom);
  222:     my ($uname) = ($r->user =~ m/([a-zA-Z0-9_\-@.]*)/);
  223:     unless ($uname =~ /^$match_username$/) {
  224:         return;
  225:     }
  226:     $udom = $r->dir_config('lonSSOUserDomain');
  227:     if ($udom eq '') {
  228:         $udom = $r->dir_config('lonDefDomain');
  229:     }
  230:     unless (($udom =~ /^$match_domain$/)) {
  231:         return;
  232:     }
  233:     my $uhome = &Apache::lonnet::homeserver($uname,$udom);
  234:     if ($uhome =~ /^(con_lost|no_host|no_such_host)$/) {
  235:         return;
  236:     }
  237:     my $handle = 
  238:         &Apache::lonwebdavauth::init_webdav_env($sessiondir,$uname,$udom,
  239:                                                 $uhome,$now,$timetolive);
  240:     if ($handle ne '') {
  241:         my $cookie = "lonDAV=$handle; path=/webdav/; secure; HttpOnly;";
  242:         $r->header_out('Set-cookie' => $cookie);
  243:         $r->send_http_header;
  244:     }
  245:     return ($handle);
  246: }
  247: 
  248: sub pubstatus {
  249:     my ($fn,$docroot,$cmtime) = @_;
  250:     my $privfn = $fn;
  251:     my $thisdisfn = $fn;
  252:     $thisdisfn=~s/^\Q$docroot\E\/priv//;
  253:     my $resfn=$docroot.'/res'.$thisdisfn;
  254:     my $targetfn = '/res'.$thisdisfn;
  255:     my $status = 'unpublished';
  256:     if (-e $resfn) {
  257:         $status = 'published';
  258:         my $same = 0;
  259:         if ((stat($resfn))[9] >= $cmtime) {
  260:             $same = 1;
  261:         } else {
  262:             if (&Apache::londiff::are_different_files($resfn,$privfn)) {
  263:                 $same = 0;
  264:             } else {
  265:                 $same = 1;
  266:             }
  267:         }
  268:         if ($same) {
  269:             if (&Apache::lonnet::metadata($targetfn,'obsolete')) {
  270:                 $status = 'obsolete';
  271:             }
  272:         }
  273:     }
  274:     return $status;
  275: }
  276: 
  277: sub recurse_dir {
  278:     my ($dirname,$docroot,$numpub) = @_;
  279:     $dirname =~ s{/$}{};
  280:     my $dirptr=16384;
  281:     if (opendir(my $dirh,$dirname)) {
  282:         my @items = readdir($dirh);
  283:         closedir($dirh);
  284:         foreach my $item (@items) {
  285:             next if ($item =~ /.+\.(log|bak|save|meta)$/);
  286:             next if ($item =~ /^\.+/);
  287:             my ($cmode,$cmtime)=(stat("$dirname/$item"))[2,9];
  288:             if (!($cmode&$dirptr)) {
  289:                 if (&pubstatus("$dirname/$item",$docroot,$cmtime) eq 'published') {
  290:                     $numpub ++;
  291:                 }
  292:             } else {
  293:                 $numpub = &recursedir("$dirname/$item",$docroot,$numpub);
  294:             }
  295:         }
  296:     }
  297:     return $numpub;
  298: }
  299: 
  300: 1;