Annotation of loncom/lti/ltiutils.pm, revision 1.13
1.1 raeburn 1: # The LearningOnline Network with CAPA
2: # Utility functions for managing LON-CAPA LTI interactions
3: #
1.13 ! raeburn 4: # $Id: ltiutils.pm,v 1.12 2018/05/30 17:22:30 raeburn Exp $
1.1 raeburn 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: package LONCAPA::ltiutils;
30:
31: use strict;
32: use Net::OAuth;
33: use Digest::SHA;
34: use UUID::Tiny ':std';
35: use Apache::lonnet;
36: use Apache::loncommon;
1.11 raeburn 37: use Apache::loncoursedata;
38: use Apache::lonuserutils;
39: use Apache::lonenc();
40: use Apache::longroup();
1.12 raeburn 41: use Apache::lonlocal;
1.10 raeburn 42: use Math::Round();
1.1 raeburn 43: use LONCAPA qw(:DEFAULT :match);
44:
45: #
46: # LON-CAPA as LTI Consumer or LTI Provider
47: #
48: # Determine if a nonce in POSTed data has expired.
49: # If unexpired, confirm it has not already been used.
50: #
51: # When LON-CAPA is operating as a Consumer, nonce checking
52: # occurs when a Tool Provider launched from an instance of
53: # an external tool in a LON-CAPA course makes a request to
54: # (a) /adm/service/roster or (b) /adm/service/passback to,
55: # respectively, retrieve a roster or store the grade for
56: # the original launch by a specific user.
57: #
58: # When LON-CAPA is operating as a Provider, nonce checking
59: # occurs when a user in course context in another LMS (the
1.4 raeburn 60: # Consumer) launches an external tool to access a LON-CAPA URL:
1.1 raeburn 61: # /adm/lti/ with LON-CAPA symb, map, or deep-link ID appended.
62: #
63:
64: sub check_nonce {
65: my ($nonce,$timestamp,$lifetime,$domain,$ltidir) = @_;
66: if (($ltidir eq '') || ($timestamp eq '') || ($timestamp =~ /^\D/) ||
67: ($lifetime eq '') || ($lifetime =~ /\D/) || ($domain eq '')) {
68: return;
69: }
70: my $now = time;
71: if (($timestamp) && ($timestamp < ($now - $lifetime))) {
72: return;
73: }
74: if ($nonce eq '') {
75: return;
76: }
77: if (-e "$ltidir/$domain/$nonce") {
78: return;
79: } else {
80: unless (-e "$ltidir/$domain") {
81: unless (mkdir("$ltidir/$domain",0755)) {
82: return;
83: }
84: }
85: if (open(my $fh,'>',"$ltidir/$domain/$nonce")) {
86: print $fh $now;
87: close($fh);
88: return 1;
89: }
90: }
91: return;
92: }
93:
94: #
95: # LON-CAPA as LTI Consumer
96: #
97: # Determine the domain and the courseID of the LON-CAPA course
98: # for which access is needed by a Tool Provider -- either to
99: # retrieve a roster or store the grade for an instance of an
100: # external tool in the course.
101: #
102:
103: sub get_loncapa_course {
104: my ($lonhost,$cid,$errors) = @_;
105: return unless (ref($errors) eq 'HASH');
106: my ($cdom,$cnum);
107: if ($cid =~ /^($match_domain)_($match_courseid)$/) {
108: my ($posscdom,$posscnum) = ($1,$2);
109: my $cprimary_id = &Apache::lonnet::domain($posscdom,'primary');
110: if ($cprimary_id eq '') {
111: $errors->{5} = 1;
112: return;
113: } else {
114: my @intdoms;
115: my $internet_names = &Apache::lonnet::get_internet_names($lonhost);
116: if (ref($internet_names) eq 'ARRAY') {
117: @intdoms = @{$internet_names};
118: }
119: my $cintdom = &Apache::lonnet::internet_dom($cprimary_id);
120: if (($cintdom ne '') && (grep(/^\Q$cintdom\E$/,@intdoms))) {
121: $cdom = $posscdom;
122: } else {
123: $errors->{6} = 1;
124: return;
125: }
126: }
127: my $chome = &Apache::lonnet::homeserver($posscnum,$posscdom);
128: if ($chome =~ /(con_lost|no_host|no_such_host)/) {
129: $errors->{7} = 1;
130: return;
131: } else {
132: $cnum = $posscnum;
133: }
134: } else {
135: $errors->{8} = 1;
136: return;
137: }
138: return ($cdom,$cnum);
139: }
140:
141: #
142: # LON-CAPA as LTI Consumer
143: #
144: # Determine the symb and (optionally) LON-CAPA user for an
145: # instance of an external tool in a course -- either to
146: # to retrieve a roster or store a grade.
147: #
148: # Use the digested symb to lookup the real symb in exttools.db
149: # and the digested userID to lookup the real userID (if needed).
150: # and extract the exttool instance and symb.
151: #
152:
153: sub get_tool_instance {
154: my ($cdom,$cnum,$digsymb,$diguser,$errors) = @_;
155: return unless (ref($errors) eq 'HASH');
156: my ($marker,$symb,$uname,$udom);
157: my @keys = ($digsymb);
158: if ($diguser) {
159: push(@keys,$diguser);
160: }
161: my %digesthash = &Apache::lonnet::get('exttools',\@keys,$cdom,$cnum);
162: if ($digsymb) {
163: $symb = $digesthash{$digsymb};
164: if ($symb) {
165: my ($map,$id,$url) = split(/___/,$symb);
166: $marker = (split(m{/},$url))[3];
167: $marker=~s/\D//g;
168: } else {
169: $errors->{9} = 1;
170: }
171: }
172: if ($diguser) {
173: if ($digesthash{$diguser} =~ /^($match_username):($match_domain)$/) {
174: ($uname,$udom) = ($1,$2);
175: } else {
176: $errors->{10} = 1;
177: }
178: return ($marker,$symb,$uname,$udom);
179: } else {
180: return ($marker,$symb);
181: }
182: }
183:
184: #
185: # LON-CAPA as LTI Consumer
186: #
187: # Retrieve data needed to validate a request from a Tool Provider
188: # for a roster or to store a grade for an instance of an external
189: # tool in a LON-CAPA course.
190: #
191: # Retrieve the Consumer key and Consumer secret from the domain
192: # configuration or the Tool Provider ID stored in the
193: # exttool_$marker db file and compare the Consumer key with the
194: # one in the POSTed data.
195: #
196: # Side effect is to populate the $toolsettings hashref with the
197: # contents of the .db file (instance of tool in course) and the
198: # $ltitools hashref with the configuration for the tool (at
199: # domain level).
200: #
201:
202: sub get_tool_secret {
203: my ($key,$marker,$symb,$cdom,$cnum,$toolsettings,$ltitools,$errors) = @_;
204: return unless ((ref($toolsettings) eq 'HASH') && (ref($ltitools) eq 'HASH') &&
205: (ref($errors) eq 'HASH'));
206: my ($consumer_secret,$nonce_lifetime);
207: if ($marker) {
208: %{$toolsettings}=&Apache::lonnet::dump('exttool_'.$marker,$cdom,$cnum);
209: if ($toolsettings->{'id'}) {
210: my $idx = $toolsettings->{'id'};
211: my %lti = &Apache::lonnet::get_domain_lti($cdom,'consumer');
212: if (ref($lti{$idx}) eq 'HASH') {
213: %{$ltitools} = %{$lti{$idx}};
214: if ($ltitools->{'key'} eq $key) {
215: $consumer_secret = $ltitools->{'secret'};
216: $nonce_lifetime = $ltitools->{'lifetime'};
217: } else {
218: $errors->{11} = 1;
219: return;
220: }
221: } else {
222: $errors->{12} = 1;
223: return;
224: }
225: } else {
226: $errors->{13} = 1;
227: return;
228: }
229: } else {
230: $errors->{14};
231: return;
232: }
233: return ($consumer_secret,$nonce_lifetime);
234: }
235:
236: #
237: # LON-CAPA as LTI Consumer
238: #
239: # Verify a signed request using the consumer_key and
240: # secret for the specific LTI Provider.
241: #
242:
243: sub verify_request {
244: my ($params,$protocol,$hostname,$requri,$reqmethod,$consumer_secret,$errors) = @_;
245: return unless (ref($errors) eq 'HASH');
246: my $request = Net::OAuth->request('request token')->from_hash($params,
247: request_url => $protocol.'://'.$hostname.$requri,
248: request_method => $reqmethod,
249: consumer_secret => $consumer_secret,);
250: unless ($request->verify()) {
251: $errors->{15} = 1;
252: return;
253: }
254: }
255:
256: #
257: # LON-CAPA as LTI Consumer
258: #
259: # Verify that an item identifier (either roster request:
260: # ext_ims_lis_memberships_id, or grade store:
261: # lis_result_sourcedid) has not been tampered with, and
262: # the secret used to create the unique identifier has not
263: # expired.
264: #
265: # Prepending the current secret (if still valid),
266: # or the previous secret (if current one is no longer valid),
267: # to a string composed of the :::-separated components
268: # must generate the result signature in the lis item ID
269: # sent by the Tool Provider.
270: #
271:
272: sub verify_lis_item {
273: my ($sigrec,$context,$digsymb,$diguser,$cdom,$cnum,$toolsettings,$ltitools,$errors) = @_;
274: return unless ((ref($toolsettings) eq 'HASH') && (ref($ltitools) eq 'HASH') &&
275: (ref($errors) eq 'HASH'));
276: my ($has_action, $valid_for);
277: if ($context eq 'grade') {
278: $has_action = $ltitools->{'passback'};
279: $valid_for = $ltitools->{'passbackvalid'}
280: } elsif ($context eq 'roster') {
281: $has_action = $ltitools->{'roster'};
282: $valid_for = $ltitools->{'rostervalid'};
283: }
284: if ($has_action) {
285: my $secret;
286: if (($toolsettings->{$context.'secretdate'} + $valid_for) > time) {
287: $secret = $toolsettings->{$context.'secret'};
288: } else {
289: $secret = $toolsettings->{'old'.$context.'secret'};
290: }
291: if ($secret) {
292: my $expected_sig;
293: if ($context eq 'grade') {
294: my $uniqid = $digsymb.':::'.$diguser.':::'.$cdom.'_'.$cnum;
1.5 raeburn 295: $expected_sig = (split(/:::/,&get_service_id($secret,$uniqid)))[0];
1.1 raeburn 296: if ($expected_sig eq $sigrec) {
297: return 1;
298: } else {
1.2 raeburn 299: $errors->{17} = 1;
1.1 raeburn 300: }
301: } elsif ($context eq 'roster') {
302: my $uniqid = $digsymb.':::'.$cdom.'_'.$cnum;
1.5 raeburn 303: $expected_sig = (split(/:::/,&get_service_id($secret,$uniqid)))[0];
1.1 raeburn 304: if ($expected_sig eq $sigrec) {
305: return 1;
306: } else {
1.2 raeburn 307: $errors->{18} = 1;
1.1 raeburn 308: }
309: }
310: } else {
1.2 raeburn 311: $errors->{19} = 1;
1.1 raeburn 312: }
313: } else {
1.2 raeburn 314: $errors->{20} = 1;
1.1 raeburn 315: }
316: return;
317: }
318:
319: #
320: # LON-CAPA as LTI Consumer
321: #
322: # Sign a request used to launch an instance of an external
1.4 raeburn 323: # tool in a LON-CAPA course, using the key and secret supplied
1.1 raeburn 324: # by the Tool Provider.
325: #
326:
327: sub sign_params {
1.3 raeburn 328: my ($url,$key,$secret,$sigmethod,$paramsref) = @_;
1.1 raeburn 329: return unless (ref($paramsref) eq 'HASH');
1.3 raeburn 330: if ($sigmethod eq '') {
331: $sigmethod = 'HMAC-SHA1';
332: }
1.9 raeburn 333: srand( time() ^ ($$ + ($$ << 15)) ); # Seed rand.
1.1 raeburn 334: my $nonce = Digest::SHA::sha1_hex(sprintf("%06x%06x",rand(0xfffff0),rand(0xfffff0)));
335: my $request = Net::OAuth->request("request token")->new(
336: consumer_key => $key,
337: consumer_secret => $secret,
338: request_url => $url,
339: request_method => 'POST',
1.3 raeburn 340: signature_method => $sigmethod,
1.1 raeburn 341: timestamp => time,
342: nonce => $nonce,
343: callback => 'about:blank',
344: extra_params => $paramsref,
345: version => '1.0',
346: );
347: $request->sign;
348: return $request->to_hash();
349: }
350:
351: #
352: # LON-CAPA as LTI Consumer
353: #
354: # Generate a signature for a unique identifier (roster request:
355: # ext_ims_lis_memberships_id, or grade store: lis_result_sourcedid)
356: #
357:
358: sub get_service_id {
359: my ($secret,$id) = @_;
360: my $sig = Digest::SHA::sha1_hex($secret.':::'.$id);
361: return $sig.':::'.$id;
362: }
363:
364: #
365: # LON-CAPA as LTI Consumer
366: #
367: # Generate and store the time-limited secret used to create the
368: # signature in a service request identifier (roster request or
369: # grade store). An existing secret past its expiration date
370: # will be stored as old<service name>secret, and a new secret
371: # <service name>secret will be stored.
372: #
373: # Secrets are specific to service name and to the tool instance
374: # (and are stored in the exttool_$marker db file).
375: # The time period a secret remains valid is determined by the
376: # domain configuration for the specific tool and the service.
377: #
378:
379: sub set_service_secret {
380: my ($cdom,$cnum,$marker,$name,$now,$toolsettings,$ltitools) = @_;
381: return unless ((ref($toolsettings) eq 'HASH') && (ref($ltitools) eq 'HASH'));
382: my $warning;
383: my ($needsnew,$oldsecret,$lifetime);
384: if ($name eq 'grade') {
385: $lifetime = $ltitools->{'passbackvalid'}
386: } elsif ($name eq 'roster') {
387: $lifetime = $ltitools->{'rostervalid'};
388: }
389: if ($toolsettings->{$name} eq '') {
390: $needsnew = 1;
391: } elsif (($toolsettings->{$name.'date'} + $lifetime) < $now) {
392: $oldsecret = $toolsettings->{$name.'secret'};
393: $needsnew = 1;
394: }
395: if ($needsnew) {
396: if (&get_tool_lock($cdom,$cnum,$marker,$name,$now) eq 'ok') {
397: my $secret = UUID::Tiny::create_uuid_as_string(UUID_V4);
398: $toolsettings->{$name.'secret'} = $secret;
399: my %secrethash = (
400: $name.'secret' => $secret,
401: $name.'secretdate' => $now,
402: );
403: if ($oldsecret ne '') {
404: $secrethash{'old'.$name.'secret'} = $oldsecret;
405: }
406: my $putres = &Apache::lonnet::put('exttool_'.$marker,
407: \%secrethash,$cdom,$cnum);
408: my $delresult = &release_tool_lock($cdom,$cnum,$marker,$name);
409: if ($delresult ne 'ok') {
410: $warning = $delresult ;
411: }
412: if ($putres eq 'ok') {
413: return 'ok';
414: }
415: } else {
416: $warning = 'Could not obtain exclusive lock';
417: }
418: } else {
419: return 'ok';
420: }
421: return;
422: }
423:
424: #
425: # LON-CAPA as LTI Consumer
426: #
427: # Add a lock key to exttools.db for the instance of an external tool
428: # when generating and storing a service secret.
429: #
430:
431: sub get_tool_lock {
432: my ($cdom,$cnum,$marker,$name,$now) = @_;
433: # get lock for tool for which secret is being set
434: my $lockhash = {
435: $name."\0".$marker."\0".'lock' => $now.':'.$env{'user.name'}.
436: ':'.$env{'user.domain'},
437: };
438: my $tries = 0;
439: my $gotlock = &Apache::lonnet::newput('exttools',$lockhash,$cdom,$cnum);
440:
441: while (($gotlock ne 'ok') && $tries <3) {
442: $tries ++;
443: sleep(1);
444: $gotlock = &Apache::lonnet::newput('exttools',$lockhash,$cdom,$cnum);
445: }
446: return $gotlock;
447: }
448:
449: #
450: # LON-CAPA as LTI Consumer
451: #
452: # Remove a lock key from exttools.db for the instance of an external
453: # tool created when generating and storing a service secret.
454: #
455:
456: sub release_tool_lock {
1.3 raeburn 457: my ($cdom,$cnum,$marker,$name) = @_;
1.1 raeburn 458: # remove lock
459: my @del_lock = ($name."\0".$marker."\0".'lock');
460: my $dellockoutcome=&Apache::lonnet::del('exttools',\@del_lock,$cdom,$cnum);
461: if ($dellockoutcome ne 'ok') {
462: return 'Warning: failed to release lock for exttool';
463: } else {
464: return 'ok';
465: }
466: }
467:
1.6 raeburn 468: #
469: # LON-CAPA as LTI Provider
470: #
471: # Use the part of the launch URL after /adm/lti to determine
472: # the scope for the current session (i.e., restricted to a
473: # single resource, to a single folder/map, or to an entire
474: # course).
475: #
476: # Returns an array containing scope: resource, map, or course
477: # and the LON-CAPA URL that is displayed post-launch, including
478: # accommodation of URL encryption, and translation of a tiny URL
479: # to the actual URL
480: #
481:
482: sub lti_provider_scope {
1.10 raeburn 483: my ($tail,$cdom,$cnum,$getunenc) = @_;
484: my ($scope,$realuri,$passkey,$unencsymb);
485: if ($tail =~ m{^/?uploaded/$cdom/$cnum/(?:default|supplemental)(?:|_\d+)\.(?:sequence|page)(|___\d+___.+)$}) {
1.6 raeburn 486: my $rest = $1;
487: if ($rest eq '') {
488: $scope = 'map';
489: $realuri = $tail;
490: } else {
1.13 ! raeburn 491: my $symb = $tail;
! 492: $symb =~ s{^/}{};
! 493: my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
1.6 raeburn 494: $realuri = &Apache::lonnet::clutter($url);
1.7 raeburn 495: if ($url =~ /\.sequence$/) {
496: $scope = 'map';
1.6 raeburn 497: } else {
1.7 raeburn 498: $scope = 'resource';
1.13 ! raeburn 499: $realuri .= '?symb='.$symb;
! 500: $passkey = $symb;
1.10 raeburn 501: if ($getunenc) {
1.13 ! raeburn 502: $unencsymb = $symb;
1.10 raeburn 503: }
1.6 raeburn 504: }
505: }
1.10 raeburn 506: } elsif ($tail =~ m{^/?res/$match_domain/$match_username/.+\.(?:sequence|page)(|___\d+___.+)$}) {
1.8 raeburn 507: my $rest = $1;
508: if ($rest eq '') {
509: $scope = 'map';
510: $realuri = $tail;
511: } else {
1.13 ! raeburn 512: my $symb = $tail;
! 513: $symb =~ s{^/?res/}{};
! 514: my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
1.8 raeburn 515: $realuri = &Apache::lonnet::clutter($url);
516: if ($url =~ /\.sequence$/) {
517: $scope = 'map';
518: } else {
519: $scope = 'resource';
1.13 ! raeburn 520: $realuri .= '?symb='.$symb;
! 521: $passkey = $symb;
1.10 raeburn 522: if ($getunenc) {
1.13 ! raeburn 523: $unencsymb = $symb;
1.10 raeburn 524: }
1.8 raeburn 525: }
526: }
1.6 raeburn 527: } elsif ($tail =~ m{^/tiny/$cdom/(\w+)$}) {
528: my $key = $1;
529: my $tinyurl;
530: my ($result,$cached)=&Apache::lonnet::is_cached_new('tiny',$cdom."\0".$key);
531: if (defined($cached)) {
532: $tinyurl = $result;
533: } else {
534: my $configuname = &Apache::lonnet::get_domainconfiguser($cdom);
535: my %currtiny = &Apache::lonnet::get('tiny',[$key],$cdom,$configuname);
536: if ($currtiny{$key} ne '') {
537: $tinyurl = $currtiny{$key};
538: &Apache::lonnet::do_cache_new('tiny',$cdom."\0".$key,$currtiny{$key},600);
539: }
540: }
541: if ($tinyurl ne '') {
542: my ($cnum,$symb) = split(/\&/,$tinyurl,2);
543: my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
544: if ($url =~ /\.(page|sequence)$/) {
545: $scope = 'map';
546: } else {
547: $scope = 'resource';
548: }
1.10 raeburn 549: $passkey = $symb;
1.6 raeburn 550: if ((&Apache::lonnet::EXT('resource.0.encrypturl',$symb) =~ /^yes$/i) &&
551: (!$env{'request.role.adv'})) {
552: $realuri = &Apache::lonenc::encrypted(&Apache::lonnet::clutter($url));
1.7 raeburn 553: if ($scope eq 'resource') {
1.6 raeburn 554: $realuri .= '?symb='.&Apache::lonenc::encrypted($symb);
555: }
556: } else {
557: $realuri = &Apache::lonnet::clutter($url);
1.7 raeburn 558: if ($scope eq 'resource') {
1.6 raeburn 559: $realuri .= '?symb='.$symb;
560: }
561: }
1.10 raeburn 562: if ($getunenc) {
563: $unencsymb = $symb;
564: }
1.6 raeburn 565: }
1.10 raeburn 566: } elsif (($tail =~ m{^/$cdom/$cnum$}) || ($tail eq '')) {
1.6 raeburn 567: $scope = 'course';
568: $realuri = '/adm/navmaps';
1.13 ! raeburn 569: $passkey = '';
1.10 raeburn 570: }
571: if ($scope eq 'map') {
572: $passkey = $realuri;
573: }
574: if (wantarray) {
575: return ($scope,$realuri,$unencsymb);
576: } else {
577: return $passkey;
578: }
579: }
580:
1.12 raeburn 581: #
582: # LON-CAPA as LTI Provider
583: #
584: # Obtain a list of course personnel and students from
585: # the LTI Consumer which launched this instance.
586: #
587:
1.11 raeburn 588: sub get_roster {
589: my ($id,$url,$ckey,$secret) = @_;
590: my %ltiparams = (
591: lti_version => 'LTI-1p0',
592: lti_message_type => 'basic-lis-readmembershipsforcontext',
593: ext_ims_lis_memberships_id => $id,
594: );
1.13 ! raeburn 595: my $hashref = &sign_params($url,$ckey,$secret,'',\%ltiparams);
1.11 raeburn 596: if (ref($hashref) eq 'HASH') {
597: my $request=new HTTP::Request('POST',$url);
598: $request->content(join('&',map {
599: my $name = escape($_);
600: "$name=" . ( ref($hashref->{$_}) eq 'ARRAY'
601: ? join("&$name=", map {escape($_) } @{$hashref->{$_}})
602: : &escape($hashref->{$_}) );
603: } keys(%{$hashref})));
604: my $response = &LONCAPA::LWPReq::makerequest('',$request,'','',10);
605: my $message=$response->status_line;
606: if (($response->is_success) && ($response->content ne '')) {
607: my %data = ();
608: my $count = 0;
609: my @state = ();
610: my @items = ('user_id','roles','person_sourcedid','person_name_given','person_name_family',
611: 'person_contact_email_primary','person_name_full','lis_result_sourcedid');
612: my $p = HTML::Parser->new
613: (
614: xml_mode => 1,
615: start_h =>
616: [sub {
617: my ($tagname, $attr) = @_;
618: push(@state,$tagname);
619: if ("@state" eq "message_response memberships member") {
620: $count ++;
621: }
622: }, "tagname, attr"],
623: text_h =>
624: [sub {
625: my ($text) = @_;
626: foreach my $item (@items) {
627: if ("@state" eq "message_response memberships member $item") {
628: $data{$count}{$item} = $text;
629: }
630: }
631: }, "dtext"],
632: end_h =>
633: [sub {
634: my ($tagname) = @_;
635: pop @state;
636: }, "tagname"],
637: );
638: $p->parse($response->content);
639: $p->eof;
640: return %data;
641: }
642: }
643: return;
644: }
645:
1.12 raeburn 646: #
647: # LON-CAPA as LTI Provider
648: #
649: # Passback a grade for a user to the LTI Consumer which originally
650: # provided the lis_result_sourcedid
651: #
652:
1.10 raeburn 653: sub send_grade {
654: my ($id,$url,$ckey,$secret,$scoretype,$total,$possible) = @_;
655: my $score;
656: if ($possible > 0) {
657: if ($scoretype eq 'ratio') {
658: $score = Math::Round::round($total).'/'.Math::Round::round($possible);
659: } elsif ($scoretype eq 'percentage') {
660: $score = (100.0*$total)/$possible;
661: $score = Math::Round::round($score);
662: } else {
663: $score = $total/$possible;
664: $score = sprintf("%.2f",$score);
665: }
666: }
667: my $date = &Apache::loncommon::utc_string(time);
668: my %ltiparams = (
669: lti_version => 'LTI-1p0',
670: lti_message_type => 'basic-lis-updateresult',
671: sourcedid => $id,
672: result_resultscore_textstring => $score,
673: result_resultscore_language => 'en-US',
674: result_resultvaluesourcedid => $scoretype,
675: result_statusofresult => 'final',
676: result_date => $date,
677: );
1.13 ! raeburn 678: my $hashref = &sign_params($url,$ckey,$secret,'',\%ltiparams);
1.10 raeburn 679: if (ref($hashref) eq 'HASH') {
680: my $request=new HTTP::Request('POST',$url);
681: $request->content(join('&',map {
682: my $name = escape($_);
683: "$name=" . ( ref($hashref->{$_}) eq 'ARRAY'
684: ? join("&$name=", map {escape($_) } @{$hashref->{$_}})
685: : &escape($hashref->{$_}) );
686: } keys(%{$hashref})));
687: my $response = &LONCAPA::LWPReq::makerequest('',$request,'','',10);
688: my $message=$response->status_line;
689: #FIXME Handle case where pass back of score to LTI Consumer failed.
1.6 raeburn 690: }
691: }
692:
1.12 raeburn 693: #
694: # LON-CAPA as LTI Provider
695: #
696: # Create a new user in LON-CAPA. If the domain's configuration
697: # includes rules for format of "official" usernames, those rules
698: # will apply when determining if a user is to be created. In
699: # additional if institutional user information is available that
700: # will be used when creating a new user account.
701: #
702:
1.11 raeburn 703: sub create_user {
704: my ($ltiref,$uname,$udom,$domdesc,$data,$alerts,$rulematch,$inst_results,
705: $curr_rules,$got_rules) = @_;
706: return unless (ref($ltiref) eq 'HASH');
707: my $checkhash = { "$uname:$udom" => { 'newuser' => 1, }, };
708: my $checks = { 'username' => 1, };
709: my ($lcauth,$lcauthparm);
710: &Apache::loncommon::user_rule_check($checkhash,$checks,$alerts,$rulematch,
711: $inst_results,$curr_rules,$got_rules);
712: my ($userchkmsg,$lcauth,$lcauthparm);
713: my $allowed = 1;
714: if (ref($alerts->{'username'}) eq 'HASH') {
715: if (ref($alerts->{'username'}{$udom}) eq 'HASH') {
716: if ($alerts->{'username'}{$udom}{$uname}) {
717: if (ref($curr_rules->{$udom}) eq 'HASH') {
718: $userchkmsg =
719: &Apache::loncommon::instrule_disallow_msg('username',$domdesc,1).
720: &Apache::loncommon::user_rule_formats($udom,$domdesc,
721: $curr_rules->{$udom}{'username'},
722: 'username');
723: }
724: $allowed = 0;
725: }
726: }
727: }
728: if ($allowed) {
729: if (ref($rulematch->{$uname.':'.$udom}) eq 'HASH') {
730: my $matchedrule = $rulematch->{$uname.':'.$udom}{'username'};
731: my ($rules,$ruleorder) =
732: &Apache::lonnet::inst_userrules($udom,'username');
733: if (ref($rules) eq 'HASH') {
734: if (ref($rules->{$matchedrule}) eq 'HASH') {
735: $lcauth = $rules->{$matchedrule}{'authtype'};
736: $lcauthparm = $rules->{$matchedrule}{'authparm'};
737: }
738: }
739: }
740: if ($lcauth eq '') {
741: $lcauth = $ltiref->{'lcauth'};
742: if ($lcauth eq 'internal') {
743: $lcauthparm = &create_passwd();
744: } else {
745: $lcauthparm = $ltiref->{'lcauthparm'};
746: }
747: }
748: } else {
749: return 'notallowed';
750: }
751: my @userinfo = ('firstname','middlename','lastname','generation','permanentemail','id');
752: my (%useinstdata,%info);
753: if (ref($ltiref->{'instdata'}) eq 'ARRAY') {
754: map { $useinstdata{$_} = 1; } @{$ltiref->{'instdata'}};
755: }
756: foreach my $item (@userinfo) {
757: if (($useinstdata{$item}) && (ref($inst_results->{$uname.':'.$udom}) eq 'HASH') &&
758: ($inst_results->{$uname.':'.$udom}{$item} ne '')) {
759: $info{$item} = $inst_results->{$uname.':'.$udom}{$item};
760: } else {
761: if ($item eq 'permanentemail') {
762: if ($data->{'permanentemail'} =~/^[^\@]+\@[^@]+$/) {
763: $info{$item} = $data->{'permanentemail'};
764: }
765: } elsif (($item eq 'firstname') || ($item eq 'lastname')) {
766: $info{$item} = $data->{$item};
767: }
768: }
769: }
770: if (($info{'middlename'} eq '') && ($data->{'fullname'} ne '')) {
771: unless ($useinstdata{'middlename'}) {
772: my $fullname = $data->{'fullname'};
773: if ($info{'firstname'}) {
774: $fullname =~ s/^\s*\Q$info{'firstname'}\E\s*//i;
775: }
776: if ($info{'lastname'}) {
777: $fullname =~ s/\s*\Q$info{'lastname'}\E\s*$//i;
778: }
779: if ($fullname ne '') {
780: $fullname =~ s/^\s+|\s+$//g;
781: if ($fullname ne '') {
782: $info{'middlename'} = $fullname;
783: }
784: }
785: }
786: }
787: if (ref($inst_results->{$uname.':'.$udom}{'inststatus'}) eq 'ARRAY') {
788: my @inststatuses = @{$inst_results->{$uname.':'.$udom}{'inststatus'}};
789: $info{'inststatus'} = join(':',map { &escape($_); } @inststatuses);
790: }
791: my $result =
792: &Apache::lonnet::modifyuser($udom,$uname,$info{'id'},
793: $lcauth,$lcauthparm,$info{'firstname'},
794: $info{'middlename'},$info{'lastname'},
795: $info{'generation'},undef,undef,
796: $info{'permanentemail'},$info{'inststatus'});
797: return $result;
798: }
799:
1.12 raeburn 800: #
801: # LON-CAPA as LTI Provider
802: #
803: # Create a password for a new user if the authentication
804: # type to assign to new users created following LTI launch is
805: # to be LON-CAPA "internal".
806: #
807:
1.11 raeburn 808: sub create_passwd {
809: my $passwd = '';
1.12 raeburn 810: srand( time() ^ ($$ + ($$ << 15)) ); # Seed rand.
1.11 raeburn 811: my @letts = ("a".."z");
812: for (my $i=0; $i<8; $i++) {
813: my $lettnum = int(rand(2));
814: my $item = '';
815: if ($lettnum) {
816: $item = $letts[int(rand(26))];
817: my $uppercase = int(rand(2));
818: if ($uppercase) {
819: $item =~ tr/a-z/A-Z/;
820: }
821: } else {
822: $item = int(rand(10));
823: }
824: $passwd .= $item;
825: }
826: return ($passwd);
827: }
828:
1.12 raeburn 829: #
830: # LON-CAPA as LTI Provider
831: #
832: # Enroll a user in a LON-CAPA course, with the specified role and (optional)
833: # section. If this is a self-enroll case, i.e., a user launched the LTI tool
834: # in the Consumer, user privs will be added to the user's environment for
835: # the new role.
836: #
837: # If this is a self-enroll case, a Course Coordinator role will only be assigned
838: # if the current user is also the course owner.
839: #
840:
1.11 raeburn 841: sub enrolluser {
1.12 raeburn 842: my ($udom,$uname,$role,$cdom,$cnum,$sec,$start,$end,$selfenroll) = @_;
1.11 raeburn 843: my $enrollresult;
844: my $area = "/$cdom/$cnum";
845: if (($role ne 'cc') && ($role ne 'co') && ($sec ne '')) {
846: $area .= '/'.$sec;
847: }
848: my $spec = $role.'.'.$area;
849: my $instcid;
850: if ($role eq 'st') {
851: $enrollresult =
852: &Apache::lonnet::modify_student_enrollment($udom,$uname,undef,undef,undef,
853: undef,undef,$sec,$end,$start,
1.12 raeburn 854: 'ltienroll',undef,$cdom.'_'.$cnum,
855: $selfenroll,'ltienroll','',$instcid);
1.11 raeburn 856: } elsif ($role =~ /^(cc|in|ta|ep)$/) {
857: $enrollresult =
858: &Apache::lonnet::assignrole($udom,$uname,$area,$role,$end,$start,
1.12 raeburn 859: undef,$selfenroll,'ltienroll');
860: }
861: if ($enrollresult eq 'ok') {
862: if ($selfenroll) {
863: my (%userroles,%newrole,%newgroups);
864: &Apache::lonnet::standard_roleprivs(\%newrole,$role,$cdom,$spec,$cnum,
865: $area);
866: &Apache::lonnet::set_userprivs(\%userroles,\%newrole,\%newgroups);
867: $userroles{'user.role.'.$spec} = $start.'.'.$end;
868: &Apache::lonnet::appenv(\%userroles,[$role,'cm']);
869: }
1.11 raeburn 870: }
871: return $enrollresult;
872: }
873:
1.12 raeburn 874: #
875: # LON-CAPA as LTI Provider
876: #
877: # Batch addition of users following LTI launch by a user
878: # with LTI Instructor status.
879: #
880: # A list of users is obtained by a call to get_roster()
881: # if the calling Consumer support the LTI extension:
882: # Context Memberships Service.
883: #
884: # If a user included in the retrieved list does not currently
885: # have a user account in LON-CAPA, an account will be created.
886: #
887: # If a user already has an account, and the same role and
888: # section assigned (currently active), then no change will
889: # be made for that user.
890: #
891: # Information available for new users (besides username and)
892: # role) may include: first name, last name, full name (from
893: # which middle name will be extracted), permanent e-mail address,
894: # and lis_result_sourcedid (for passback of grades).
895: #
896: # If grades are to be passed back, the passback url will be
897: # the same as for the current user's session.
898: #
899: # The roles which may be assigned will be determined from the
900: # LTI roles included in the retrieved roster, and the mapping
901: # of LTI roles to LON-CAPA roles configured for this LTI Consumer
902: # in the domain configuration.
903: #
904: # Course Coordinator roles will only be assigned if the current
905: # user is also the course owner.
906: #
907: # The domain configuration for the corresponding Consumer can include
908: # a section to assign to LTI users. If the roster includes students
909: # any existing student roles with a different section will be expired,
910: # and a role in the LTI section will be assigned.
911: #
912: # For non-student rules (excluding Course Coordinator) a role will be
913: # assigned with the LTI section )or no section, if one is not rquired.
914: #
915:
1.11 raeburn 916: sub batchaddroster {
917: my ($item) = @_;
918: return unless(ref($item) eq 'HASH');
919: return unless (ref($item->{'ltiref'}) eq 'HASH');
920: my ($cdom,$cnum) = split(/_/,$item->{'cid'});
921: my $udom = $cdom;
922: my $id = $item->{'id'};
923: my $url = $item->{'url'};
924: my @intdoms;
925: my $intdomsref = $item->{'intdoms'};
926: if (ref($intdomsref) eq 'ARRAY') {
927: @intdoms = @{$intdomsref};
928: }
929: my $uriscope = $item->{'uriscope'};
930: my $ckey = $item->{'ltiref'}->{'key'};
931: my $secret = $item->{'ltiref'}->{'secret'};
932: my $section = $item->{'ltiref'}->{'section'};
933: $section =~ s/\W//g;
934: if ($section eq 'none') {
935: undef($section);
936: } elsif ($section ne '') {
937: my %curr_groups =
938: &Apache::longroup::coursegroups($cdom,$cnum);
939: if (exists($curr_groups{$section})) {
940: undef($section);
941: }
942: }
943: my (%maproles,@possroles);
944: if (ref($item->{'ltiref'}->{'maproles'}) eq 'HASH') {
945: %maproles = %{$item->{'ltiref'}->{'maproles'}};
946: }
947: if (ref($item->{'possroles'}) eq 'ARRAY') {
948: @possroles = @{$item->{'possroles'}};
949: }
950: if (($ckey ne '') && ($secret ne '') && ($id ne '') && ($url ne '')) {
951: my %data = &get_roster($id,$url,$ckey,$secret);
952: if (keys(%data) > 0) {
953: my (%rulematch,%inst_results,%curr_rules,%got_rules,%alerts,%info);
954: my %coursehash = &Apache::lonnet::coursedescription($cdom.'_'.$cnum);
955: my $start = $coursehash{'default_enrollment_start_date'};
956: my $end = $coursehash{'default_enrollment_end_date'};
957: my $domdesc = &Apache::lonnet::domain($udom,'description');
958: my $roster = &Apache::loncoursedata::get_classlist($cdom,$cnum);
959: my $status = &Apache::loncoursedata::CL_STATUS;
960: my $cend = &Apache::loncoursedata::CL_END;
961: my $cstart = &Apache::loncoursedata::CL_START;
962: my $lockedtype=&Apache::loncoursedata::CL_LOCKEDTYPE;
963: my $sec=&Apache::loncoursedata::CL_SECTION;
964: my (@activestudents,@futurestudents,@excludedstudents,@localstudents,%currlist,%advroles);
965: if (grep(/^st$/,@possroles)) {
966: foreach my $user (keys(%{$roster})) {
967: if ($user =~ m/^(.+):$cdom$/) {
968: my $stuname = $1;
969: if ($roster->{$user}[$status] eq "Active") {
970: push(@activestudents,$stuname);
971: @{$currlist{$stuname}} = @{$roster->{$user}};
972: push(@localstudents,$stuname);
973: } elsif (($roster->{$user}[$cstart] > time) && ($roster->{$user}[$cend] > time ||
974: $roster->{$user}[$cend] == 0 || $roster->{$user}[$cend] eq '')) {
975: push(@futurestudents,$stuname);
976: @{$currlist{$stuname}} = @{$roster->{$user}};
977: push(@localstudents,$stuname);
978: } elsif ($roster->{$user}[$lockedtype] == 1) {
979: push(@excludedstudents,$stuname);
980: }
981: }
982: }
983: }
984: if ((@possroles > 1) || ((@possroles == 1) && (!grep(/^st$/,@possroles)))) {
985: my %personnel = &Apache::lonnet::get_course_adv_roles($item->{'cid'},1);
986: foreach my $item (keys(%personnel)) {
987: my ($role,$currsec) = split(/:/,$item);
988: if ($currsec eq '') {
989: $currsec = 'none';
990: }
991: foreach my $user (split(/,/,$personnel{$item})) {
992: push(@{$advroles{$user}{$role}},$currsec);
993: }
994: }
995: }
996: if (($end == 0) || ($end > time) || (@localstudents > 0)) {
997: my (%passback,$pbnum,$numadv);
998: $numadv = 0;
999: foreach my $i (sort { $a <=> $b } keys(%data)) {
1000: if (ref($data{$i}) eq 'HASH') {
1001: my $entry = $data{$i};
1002: my $user = $entry->{'person_sourcedid'};
1003: my $uname;
1004: if ($user =~ /^($match_username):($match_domain)$/) {
1005: $uname = $1;
1006: my $possudom = $2;
1007: if ($possudom ne $udom) {
1008: my $uintdom = &Apache::lonnet::domain($possudom,'primary');
1009: if (($uintdom ne '') && (grep(/^\Q$uintdom\E$/,@intdoms))) {
1010: $udom = $possudom;
1011: }
1012: }
1013: } elsif ($uname =~ /^match_username$/) {
1014: $uname = $user;
1015: } else {
1016: next;
1017: }
1018: my $uhome = &Apache::lonnet::homeserver($uname,$udom);
1019: if ($uhome eq 'no_host') {
1020: my %data;
1021: $data{'permanentemail'} = $entry->{'person_contact_email_primary'};
1022: $data{'lastname'} = $entry->{'person_name_family'};
1023: $data{'firstname'} = $entry->{'person_name_given'};
1024: $data{'fullname'} = $entry->{'person_name_full'};
1025: my $addresult =
1026: &create_user($item->{'ltiref'},$uname,$udom,
1027: $domdesc,\%data,\%alerts,\%rulematch,
1028: \%inst_results,\%curr_rules,\%got_rules);
1029: next unless ($addresult eq 'ok');
1030: }
1031: if ($env{'request.lti.passbackurl'}) {
1032: if ($entry->{'lis_result_sourcedid'} ne '') {
1033: unless ($pbnum) {
1034: ($pbnum,my $error) = &store_passbackurl($env{'request.lti.login'},
1035: $env{'request.lti.passbackurl'},
1036: $cdom,$cnum);
1037: if ($pbnum eq '') {
1038: $pbnum = $env{'request.lti.passbackurl'};
1039: }
1040: }
1041: $passback{$uname."\0".$uriscope."\0".$env{'request.lti.sourcecrs'}."\0".$env{'request.lti.login'}} =
1042: $pbnum."\0".$entry->{'lis_result_sourcedid'};
1043: }
1044: }
1045: my $rolestr = $entry->{'roles'};
1046: my ($lcrolesref) = &get_lc_roles($rolestr,\@possroles,\%maproles);
1047: my @lcroles = @{$lcrolesref};
1048: if (@lcroles) {
1049: if (grep(/^st$/,@lcroles)) {
1050: my $addstu;
1051: if (!grep(/^\Q$uname\E$/,@excludedstudents)) {
1052: if (grep(/^\Q$uname\E$/,@localstudents)) {
1053: # Check for section changes
1054: if ($currlist{$uname}[$sec] ne $section) {
1055: $addstu = 1;
1056: &Apache::lonuserutils::modifystudent($udom,$uname,$cdom.'_'.$cnum,
1057: undef,undef,'course');
1058: } elsif (grep(/^\Q$uname\E$/,@futurestudents)) {
1059: # Check for access date changes for students with access starting in the future.
1060: my $datechange = &datechange_check($currlist{$uname}[$cstart],
1061: $currlist{$uname}[$cend],
1062: $start,$end);
1063: if ($datechange) {
1064: $addstu = 1;
1065: }
1066: }
1067: } else {
1068: $addstu = 1;
1069: }
1070: }
1071: unless ($addstu) {
1072: pop(@lcroles);
1073: }
1074: }
1075: my @okroles;
1076: if (@lcroles) {
1077: foreach my $role (@lcroles) {
1078: unless (($role eq 'st') || (keys(%advroles) == 0)) {
1079: if (exists($advroles{$uname.':'.$udom})) {
1080: if ((ref($advroles{$uname.':'.$udom}) eq 'HASH') &&
1081: (ref($advroles{$uname.':'.$udom}{$role}) eq 'ARRAY')) {
1082: if (($section eq '') || ($role eq 'cc') || ($role eq 'co')) {
1083: next if (grep(/^none$/,@{$advroles{$uname.':'.$udom}{$role}}));
1084: } else {
1085: next if (grep(/^\Q$sec\E$/,@{$advroles{$uname.':'.$udom}{$role}}));
1086: }
1087: }
1088: }
1089: }
1090: push(@okroles,$role);
1091: }
1092: }
1093: if (@okroles) {
1094: my $permanentemail = $entry->{'person_contact_email_primary'};
1095: my $lastname = $entry->{'person_name_family'};
1096: my $firstname = $entry->{'person_name_given'};
1097: foreach my $role (@okroles) {
1098: my $enrollresult = &enrolluser($udom,$uname,$role,$cdom,$cnum,
1099: $section,$start,$end);
1100: if (($enrollresult eq 'ok') && ($role ne 'st')) {
1101: $numadv ++;
1102: }
1103: }
1104: }
1105: }
1106: }
1107: }
1108: if (keys(%passback)) {
1109: &Apache::lonnet::put('nohist_lti_passback',\%passback,$cdom,$cnum);
1110: }
1111: if ($numadv) {
1112: &Apache::lonnet::flushcourselogs();
1113: }
1114: }
1115: }
1116: }
1117: return;
1118: }
1119:
1.12 raeburn 1120: #
1121: # LON-CAPA as LTI Provider
1122: #
1123: # Gather a list of available LON-CAPA roles derived
1124: # from a comma separated list of LTI roles.
1125: #
1126: # Which LON-CAPA roles are assignable by the current user
1127: # and how LTI roles map to LON-CAPA roles (as defined in
1128: # the domain configuration for the specific Consumer) are
1129: # factored in when compiling the list of available roles.
1130: #
1131: # Inputs: 3
1132: # $rolestr - comma separated list of LTI roles.
1133: # $allowedroles - reference to array of assignable LC roles
1134: # $maproles - ref to HASH of mapping of LTI roles to LC roles
1135: #
1136: # Outputs: 2
1137: # (a) reference to array of available LC roles.
1138: # (b) reference to array of LTI roles.
1139: #
1140:
1.11 raeburn 1141: sub get_lc_roles {
1142: my ($rolestr,$allowedroles,$maproles) = @_;
1143: my (@ltiroles,@lcroles);
1144: my @ltiroleorder = ('Instructor','TeachingAssistant','Mentor','Learner');
1145: if ($rolestr =~ /,/) {
1146: my @possltiroles = split(/\s*,\s*/,$rolestr);
1147: foreach my $ltirole (@ltiroleorder) {
1148: if (grep(/^\Q$ltirole\E$/,@possltiroles)) {
1149: push(@ltiroles,$ltirole);
1150: }
1151: }
1152: } else {
1153: my $singlerole = $rolestr;
1154: $singlerole =~ s/^\s|\s+$//g;
1155: if ($singlerole ne '') {
1156: if (grep(/^\Q$singlerole\E$/,@ltiroleorder)) {
1157: @ltiroles = ($singlerole);
1158: }
1159: }
1160: }
1161: if (@ltiroles) {
1162: my %possroles;
1163: map { $possroles{$maproles->{$_}} = 1; } @ltiroles;
1164: if (keys(%possroles) > 0) {
1165: if (ref($allowedroles) eq 'ARRAY') {
1166: foreach my $item (@{$allowedroles}) {
1167: if (($item eq 'co') || ($item eq 'cc')) {
1168: if ($possroles{'cc'}) {
1169: push(@lcroles,$item);
1170: }
1171: } elsif ($possroles{$item}) {
1172: push(@lcroles,$item);
1173: }
1174: }
1175: }
1176: }
1177: }
1178: return (\@lcroles,\@ltiroles);
1179: }
1180:
1.12 raeburn 1181: #
1182: # LON-CAPA as LTI Provider
1183: #
1184: # Compares current start and dates for a user's role
1185: # with dates to apply for the same user/role to
1186: # determine if there is a change between the current
1187: # ones and the updated ones.
1188: #
1189:
1.11 raeburn 1190: sub datechange_check {
1191: my ($oldstart,$oldend,$startdate,$enddate) = @_;
1192: my $datechange = 0;
1193: unless ($oldstart eq $startdate) {
1194: $datechange = 1;
1195: }
1196: if (!$datechange) {
1197: if (!$oldend) {
1198: if ($enddate) {
1199: $datechange = 1;
1200: }
1201: } elsif ($oldend ne $enddate) {
1202: $datechange = 1;
1203: }
1204: }
1205: return $datechange;
1206: }
1207:
1.12 raeburn 1208: #
1209: # LON-CAPA as LTI Provider
1210: #
1211: # Store the URL used by a specific LTI Consumer to process grades passed back
1212: # by an LTI Provider.
1213: #
1214:
1.11 raeburn 1215: sub store_passbackurl {
1216: my ($ltinum,$pburl,$cdom,$cnum) = @_;
1217: my %history = &Apache::lonnet::restore($ltinum,'passbackurl',$cdom,$cnum);
1218: my ($pbnum,$version,$error);
1219: if ($history{'version'}) {
1220: $version = $history{'version'};
1221: for (my $i=1; $i<=$version; $i++) {
1222: if ($history{$i.':pburl'} eq $pburl) {
1223: $pbnum = $i;
1224: last;
1225: }
1226: }
1227: } else {
1228: $version = 0;
1229: }
1230: if ($pbnum eq '') {
1231: # get lock on passbackurl db
1232: my $now = time;
1233: my $lockhash = {
1234: 'lock'."\0".$ltinum."\0".$now => $env{'user.name'}.':'.$env{'user.domain'},
1235: };
1236: my $tries = 0;
1237: my $gotlock = &Apache::lonnet::newput('passbackurl',$lockhash,$cdom,$cnum);
1238: while (($gotlock ne 'ok') && ($tries<3)) {
1239: $tries ++;
1240: sleep 1;
1241: $gotlock = &Apache::lonnet::newput('passbackurl',$lockhash,$cdom.$cnum);
1242: }
1243: if ($gotlock eq 'ok') {
1244: if (&Apache::lonnet::store_userdata({pburl => $pburl},
1245: $ltinum,'passbackurl',$cdom,$cnum) eq 'ok') {
1246: $pbnum = 1+$version;
1247: }
1248: my $dellock = &Apache::lonnet::del('passbackurl',['lock'."\0".$ltinum."\0".$now],$cdom,$cnum);
1249: unless ($dellock eq 'ok') {
1250: $error = &mt('error: could not release lockfile');
1251: }
1252: } else {
1253: $error = &mt('error: could not obtain lockfile');
1254: }
1255: }
1256: return ($pbnum,$error);
1257: }
1258:
1.1 raeburn 1259: 1;
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