Commit | Line | Data |
9e447f9d |
1 | #!/usr/bin/perl |
2 | |
3 | package Catalyst::Plugin::Session; |
4 | use base qw/Class::Accessor::Fast/; |
5 | |
6 | use strict; |
7 | use warnings; |
8 | |
9 | use NEXT; |
10 | use Catalyst::Exception (); |
9a9252c2 |
11 | use Digest (); |
12 | use overload (); |
d44bc687 |
13 | use Object::Signature (); |
9e447f9d |
14 | |
5d8cc4c7 |
15 | our $VERSION = "0.05"; |
37160715 |
16 | |
ab634fee |
17 | my @session_data_accessors; # used in delete_session |
9e447f9d |
18 | BEGIN { |
4207ce8d |
19 | __PACKAGE__->mk_accessors( |
ab634fee |
20 | "_session_delete_reason", |
21 | @session_data_accessors = qw/ |
4207ce8d |
22 | _sessionid |
23 | _session |
24 | _session_expires |
25 | _session_data_sig |
4207ce8d |
26 | _flash |
27 | _flash_stale_keys |
28 | / |
29 | ); |
9e447f9d |
30 | } |
31 | |
32 | sub setup { |
9a9252c2 |
33 | my $c = shift; |
34 | |
35 | $c->NEXT::setup(@_); |
36 | |
37 | $c->check_session_plugin_requirements; |
38 | $c->setup_session; |
39 | |
40 | return $c; |
9e447f9d |
41 | } |
42 | |
43 | sub check_session_plugin_requirements { |
9a9252c2 |
44 | my $c = shift; |
9e447f9d |
45 | |
9a9252c2 |
46 | unless ( $c->isa("Catalyst::Plugin::Session::State") |
47 | && $c->isa("Catalyst::Plugin::Session::Store") ) |
48 | { |
49 | my $err = |
50 | ( "The Session plugin requires both Session::State " |
51 | . "and Session::Store plugins to be used as well." ); |
9e447f9d |
52 | |
9a9252c2 |
53 | $c->log->fatal($err); |
54 | Catalyst::Exception->throw($err); |
55 | } |
9e447f9d |
56 | } |
57 | |
58 | sub setup_session { |
9a9252c2 |
59 | my $c = shift; |
9e447f9d |
60 | |
9a9252c2 |
61 | my $cfg = ( $c->config->{session} ||= {} ); |
9e447f9d |
62 | |
9a9252c2 |
63 | %$cfg = ( |
64 | expires => 7200, |
65 | verify_address => 1, |
66 | %$cfg, |
67 | ); |
9e447f9d |
68 | |
9a9252c2 |
69 | $c->NEXT::setup_session(); |
9e447f9d |
70 | } |
71 | |
19c130c2 |
72 | sub prepare_action { |
73 | my $c = shift; |
74 | |
4207ce8d |
75 | if ( $c->config->{session}{flash_to_stash} |
76 | and $c->_sessionid |
77 | and my $flash_data = $c->flash ) |
78 | { |
19c130c2 |
79 | @{ $c->stash }{ keys %$flash_data } = values %$flash_data; |
80 | } |
81 | |
82 | $c->NEXT::prepare_action(@_); |
83 | } |
84 | |
9e447f9d |
85 | sub finalize { |
9a9252c2 |
86 | my $c = shift; |
9e447f9d |
87 | |
9b0fa2a6 |
88 | $c->_save_session; |
89 | $c->_save_flash; |
90 | |
91 | $c->NEXT::finalize(@_); |
92 | } |
93 | |
94 | sub _save_session { |
95 | my $c = shift; |
4207ce8d |
96 | |
ea972e9a |
97 | if ( my $sid = $c->_sessionid ) { |
9e447f9d |
98 | |
6687905d |
99 | # all sessions are extended at the end of the request |
100 | my $now = time; |
101 | |
102 | if ( my $expires = $c->session_expires ) { |
103 | $c->store_session_data( "expires:$sid" => $expires ); |
104 | } |
7a02371f |
105 | |
6687905d |
106 | if ( my $session_data = $c->_session ) { |
d44bc687 |
107 | |
108 | no warnings 'uninitialized'; |
4207ce8d |
109 | if ( Object::Signature::signature($session_data) ne |
110 | $c->_session_data_sig ) |
111 | { |
d44bc687 |
112 | $session_data->{__updated} = $now; |
113 | $c->store_session_data( "session:$sid" => $session_data ); |
114 | } |
ea972e9a |
115 | } |
9a9252c2 |
116 | } |
9b0fa2a6 |
117 | } |
9a9252c2 |
118 | |
9b0fa2a6 |
119 | sub _save_flash { |
120 | my $c = shift; |
121 | |
ea972e9a |
122 | if ( my $sid = $c->_sessionid ) { |
23fbca00 |
123 | if ( my $flash_data = $c->_flash ) { |
124 | delete @{$flash_data}{ @{ $c->_flash_stale_keys || [] } }; |
4207ce8d |
125 | |
23fbca00 |
126 | if (%$flash_data) { |
127 | $c->store_session_data( "flash:$sid", $flash_data ); |
128 | } |
129 | else { |
130 | $c->delete_session_data("flash:$sid"); |
131 | } |
ea972e9a |
132 | } |
9b0fa2a6 |
133 | } |
9e447f9d |
134 | } |
135 | |
b7acf64e |
136 | sub _load_session { |
137 | my $c = shift; |
138 | |
29d15411 |
139 | if ( my $sid = $c->_sessionid ) { |
6687905d |
140 | if ( $c->session_expires ) { # > 0 |
0974ac06 |
141 | |
6687905d |
142 | my $session_data = $c->get_session_data("session:$sid"); |
143 | $c->_session($session_data); |
3f182468 |
144 | |
6687905d |
145 | no warnings 'uninitialized'; # ne __address |
146 | if ( $c->config->{session}{verify_address} |
147 | && $session_data->{__address} ne $c->request->address ) |
148 | { |
149 | $c->log->warn( |
150 | "Deleting session $sid due to address mismatch (" |
151 | . $session_data->{__address} . " != " |
152 | . $c->request->address . ")", |
153 | ); |
154 | $c->delete_session("address mismatch"); |
155 | return; |
156 | } |
4207ce8d |
157 | |
6687905d |
158 | $c->log->debug(qq/Restored session "$sid"/) if $c->debug; |
168d6819 |
159 | $c->_session_data_sig( Object::Signature::signature($session_data) ) if $session_data; |
6687905d |
160 | $c->_expire_session_keys; |
4207ce8d |
161 | |
6687905d |
162 | return $session_data; |
3f182468 |
163 | } |
9a9252c2 |
164 | } |
29d15411 |
165 | |
4207ce8d |
166 | return; |
b7acf64e |
167 | } |
9a9252c2 |
168 | |
9b0fa2a6 |
169 | sub _load_flash { |
170 | my $c = shift; |
171 | |
172 | if ( my $sid = $c->_sessionid ) { |
4207ce8d |
173 | if ( my $flash_data = $c->_flash |
174 | || $c->_flash( $c->get_session_data("flash:$sid") ) ) |
175 | { |
176 | $c->_flash_stale_keys( [ keys %$flash_data ] ); |
9b0fa2a6 |
177 | return $flash_data; |
178 | } |
179 | } |
180 | |
181 | return undef; |
182 | } |
183 | |
d44bc687 |
184 | sub _expire_session_keys { |
b7acf64e |
185 | my ( $c, $data ) = @_; |
186 | |
187 | my $now = time; |
188 | |
4207ce8d |
189 | my $expiry = ( $data || $c->_session || {} )->{__expire_keys} || {}; |
190 | foreach my $key ( grep { $expiry->{$_} < $now } keys %$expiry ) { |
b7acf64e |
191 | delete $c->_session->{$key}; |
192 | delete $expiry->{$key}; |
193 | } |
9e447f9d |
194 | } |
195 | |
196 | sub delete_session { |
9a9252c2 |
197 | my ( $c, $msg ) = @_; |
9e447f9d |
198 | |
9a9252c2 |
199 | # delete the session data |
29d15411 |
200 | my $sid = $c->_sessionid || return; |
4207ce8d |
201 | $c->delete_session_data("${_}:${sid}") for qw/session expires flash/; |
9e447f9d |
202 | |
9a9252c2 |
203 | # reset the values in the context object |
ab634fee |
204 | # see the BEGIN block |
205 | $c->$_(undef) for @session_data_accessors; |
6687905d |
206 | |
29d15411 |
207 | $c->_session_delete_reason($msg); |
208 | } |
209 | |
210 | sub session_delete_reason { |
211 | my $c = shift; |
212 | |
4207ce8d |
213 | $c->_load_session |
214 | if ( $c->_sessionid && !$c->_session ); # must verify session data |
29d15411 |
215 | |
4207ce8d |
216 | $c->_session_delete_reason(@_); |
9e447f9d |
217 | } |
218 | |
6687905d |
219 | sub session_expires { |
220 | my ( $c, $should_create ) = @_; |
221 | |
222 | $c->_session_expires || do { |
223 | if ( my $sid = $c->_sessionid ) { |
224 | my $now = time; |
225 | |
226 | if ( !$should_create ) { |
227 | if ( ( $c->get_session_data("expires:$sid") || 0 ) < $now ) { |
228 | |
229 | # session expired |
230 | $c->log->debug("Deleting session $sid (expired)") |
231 | if $c->debug; |
232 | $c->delete_session("session expired"); |
233 | return 0; |
234 | } |
235 | } |
236 | |
237 | return $c->_session_expires( |
238 | $now + $c->config->{session}{expires} ); |
239 | } |
240 | }; |
241 | } |
242 | |
0974ac06 |
243 | sub sessionid { |
4207ce8d |
244 | my $c = shift; |
245 | |
246 | if (@_) { |
bab8b74b |
247 | if($c->_sessionid()) { |
248 | $c->log->warn('Session ID already set, ignoring.'); |
249 | return $c->_sessionid(); |
250 | } |
4207ce8d |
251 | if ( $c->validate_session_id( my $sid = shift ) ) { |
252 | $c->_sessionid($sid); |
29d15411 |
253 | return unless defined wantarray; |
4207ce8d |
254 | } |
255 | else { |
256 | my $err = "Tried to set invalid session ID '$sid'"; |
257 | $c->log->error($err); |
258 | Catalyst::Exception->throw($err); |
259 | } |
260 | } |
261 | |
262 | $c->_load_session |
263 | if ( $c->_sessionid && !$c->_session ); # must verify session data |
264 | |
265 | return $c->_sessionid; |
0974ac06 |
266 | } |
267 | |
268 | sub validate_session_id { |
4207ce8d |
269 | my ( $c, $sid ) = @_; |
0974ac06 |
270 | |
4207ce8d |
271 | $sid and $sid =~ /^[a-f\d]+$/i; |
0974ac06 |
272 | } |
273 | |
9e447f9d |
274 | sub session { |
9a9252c2 |
275 | my $c = shift; |
9e447f9d |
276 | |
29d15411 |
277 | $c->_session || $c->_load_session || do { |
78476ce0 |
278 | $c->create_session_id; |
9e447f9d |
279 | |
29d15411 |
280 | $c->initialize_session_data; |
4207ce8d |
281 | }; |
9e447f9d |
282 | } |
283 | |
873f7011 |
284 | sub flash { |
285 | my $c = shift; |
78476ce0 |
286 | $c->_flash || $c->_load_flash || do { |
287 | $c->create_session_id; |
288 | $c->_flash( {} ); |
4207ce8d |
289 | } |
873f7011 |
290 | } |
291 | |
b7acf64e |
292 | sub session_expire_key { |
293 | my ( $c, %keys ) = @_; |
294 | |
295 | my $now = time; |
4207ce8d |
296 | @{ $c->session->{__expire_keys} }{ keys %keys } = |
297 | map { $now + $_ } values %keys; |
b7acf64e |
298 | } |
299 | |
9e447f9d |
300 | sub initialize_session_data { |
9a9252c2 |
301 | my $c = shift; |
9e447f9d |
302 | |
9a9252c2 |
303 | my $now = time; |
9e447f9d |
304 | |
4207ce8d |
305 | return $c->_session( |
306 | { |
307 | __created => $now, |
308 | __updated => $now, |
309 | |
310 | ( |
311 | $c->config->{session}{verify_address} |
312 | ? ( __address => $c->request->address ) |
313 | : () |
314 | ), |
315 | } |
316 | ); |
9e447f9d |
317 | } |
318 | |
9e447f9d |
319 | sub generate_session_id { |
320 | my $c = shift; |
321 | |
322 | my $digest = $c->_find_digest(); |
323 | $digest->add( $c->session_hash_seed() ); |
324 | return $digest->hexdigest; |
325 | } |
326 | |
78476ce0 |
327 | sub create_session_id { |
328 | my $c = shift; |
329 | |
330 | if ( !$c->_sessionid ) { |
331 | my $sid = $c->generate_session_id; |
332 | |
333 | $c->log->debug(qq/Created session "$sid"/) if $c->debug; |
334 | |
335 | $c->sessionid($sid); |
6687905d |
336 | $c->session_expires(1); |
78476ce0 |
337 | } |
338 | } |
339 | |
9e447f9d |
340 | my $counter; |
9a9252c2 |
341 | |
9e447f9d |
342 | sub session_hash_seed { |
9a9252c2 |
343 | my $c = shift; |
344 | |
345 | return join( "", ++$counter, time, rand, $$, {}, overload::StrVal($c), ); |
9e447f9d |
346 | } |
347 | |
348 | my $usable; |
9a9252c2 |
349 | |
9e447f9d |
350 | sub _find_digest () { |
9a9252c2 |
351 | unless ($usable) { |
d44bc687 |
352 | foreach my $alg (qw/SHA-1 SHA-256 MD5/) { |
4207ce8d |
353 | if ( eval { Digest->new($alg) } ) { |
5faaa4b0 |
354 | $usable = $alg; |
355 | last; |
356 | } |
7d139eeb |
357 | } |
4207ce8d |
358 | Catalyst::Exception->throw( |
9a9252c2 |
359 | "Could not find a suitable Digest module. Please install " |
4207ce8d |
360 | . "Digest::SHA1, Digest::SHA, or Digest::MD5" ) |
361 | unless $usable; |
9a9252c2 |
362 | } |
9e447f9d |
363 | |
364 | return Digest->new($usable); |
365 | } |
366 | |
99b2191e |
367 | sub dump_these { |
368 | my $c = shift; |
369 | |
370 | ( |
371 | $c->NEXT::dump_these(), |
372 | |
373 | $c->sessionid |
374 | ? ( [ "Session ID" => $c->sessionid ], [ Session => $c->session ], ) |
375 | : () |
376 | ); |
377 | } |
378 | |
9e447f9d |
379 | __PACKAGE__; |
380 | |
381 | __END__ |
382 | |
383 | =pod |
384 | |
385 | =head1 NAME |
386 | |
387 | Catalyst::Plugin::Session - Generic Session plugin - ties together server side |
fb1a4ac3 |
388 | storage and client side state required to maintain session data. |
9e447f9d |
389 | |
390 | =head1 SYNOPSIS |
391 | |
8f0b4c16 |
392 | # To get sessions to "just work", all you need to do is use these plugins: |
393 | |
394 | use Catalyst qw/ |
395 | Session |
396 | Session::Store::FastMmap |
397 | Session::State::Cookie |
398 | /; |
399 | |
400 | # you can replace Store::FastMmap with Store::File - both have sensible |
401 | # default configurations (see their docs for details) |
402 | |
403 | # more complicated backends are available for other scenarios (DBI storage, |
404 | # etc) |
405 | |
406 | |
407 | # after you've loaded the plugins you can save session data |
408 | # For example, if you are writing a shopping cart, it could be implemented |
409 | # like this: |
9e447f9d |
410 | |
229a5b53 |
411 | sub add_item : Local { |
412 | my ( $self, $c ) = @_; |
413 | |
414 | my $item_id = $c->req->param("item"); |
415 | |
8f0b4c16 |
416 | # $c->session is a hash ref, a bit like $c->stash |
417 | # the difference is that it' preserved across requests |
229a5b53 |
418 | |
419 | push @{ $c->session->{items} }, $item_id; |
420 | |
421 | $c->forward("MyView"); |
422 | } |
423 | |
424 | sub display_items : Local { |
425 | my ( $self, $c ) = @_; |
426 | |
427 | # values in $c->session are restored |
428 | $c->stash->{items_to_display} = |
8f0b4c16 |
429 | [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ]; |
229a5b53 |
430 | |
431 | $c->forward("MyView"); |
432 | } |
433 | |
9e447f9d |
434 | =head1 DESCRIPTION |
435 | |
436 | The Session plugin is the base of two related parts of functionality required |
437 | for session management in web applications. |
438 | |
439 | The first part, the State, is getting the browser to repeat back a session key, |
440 | so that the web application can identify the client and logically string |
441 | several requests together into a session. |
442 | |
443 | The second part, the Store, deals with the actual storage of information about |
444 | the client. This data is stored so that the it may be revived for every request |
445 | made by the same client. |
446 | |
447 | This plugin links the two pieces together. |
448 | |
8f0b4c16 |
449 | =head1 RECCOMENDED BACKENDS |
450 | |
451 | =over 4 |
452 | |
453 | =item Session::State::Cookie |
454 | |
455 | The only really sane way to do state is using cookies. |
456 | |
457 | =item Session::Store::File |
458 | |
459 | A portable backend, based on Cache::File. |
460 | |
461 | =item Session::Store::FastMmap |
462 | |
463 | A fast and flexible backend, based on Cache::FastMmap. |
464 | |
465 | =back |
466 | |
9e447f9d |
467 | =head1 METHODS |
468 | |
469 | =over 4 |
470 | |
471 | =item sessionid |
472 | |
473 | An accessor for the session ID value. |
474 | |
475 | =item session |
476 | |
477 | Returns a hash reference that might contain unserialized values from previous |
478 | requests in the same session, and whose modified value will be saved for future |
479 | requests. |
480 | |
481 | This method will automatically create a new session and session ID if none |
482 | exists. |
483 | |
ab634fee |
484 | =item session_expires |
485 | |
486 | =item session_expires $reset |
487 | |
488 | This method returns the time when the current session will expire, or 0 if |
489 | there is no current session. If there is a session and it already expired, it |
490 | will delete the session and return 0 as well. |
491 | |
492 | If the C<$reset> parameter is true, and there is a session ID the expiry time |
493 | will be reset to the current time plus the time to live (see |
494 | L</CONFIGURATION>). This is used when creating a new session. |
495 | |
07e714d2 |
496 | =item flash |
497 | |
498 | This is like Ruby on Rails' flash data structure. Think of it as a stash that |
44ab6d1c |
499 | lasts for longer than one request, letting you redirect instead of forward. |
500 | |
501 | The flash data will be cleaned up only on requests on which actually use |
502 | $c->flash (thus allowing multiple redirections), and the policy is to delete |
503 | all the keys which were present at the time the data was loaded just before the |
504 | data is saved. |
07e714d2 |
505 | |
506 | sub moose : Local { |
507 | my ( $self, $c ) = @_; |
508 | |
509 | $c->flash->{beans} = 10; |
510 | $c->response->redirect( $c->uri_for("foo") ); |
511 | } |
512 | |
513 | sub foo : Local { |
514 | my ( $self, $c ) = @_; |
515 | |
516 | my $value = $c->flash->{beans}; |
517 | |
518 | # ... |
519 | |
520 | $c->response->redirect( $c->uri_for("bar") ); |
521 | } |
522 | |
523 | sub bar : Local { |
524 | my ( $self, $c ) = @_; |
525 | |
526 | if ( exists $c->flash->{beans} ) { # false |
527 | |
528 | } |
529 | } |
530 | |
9e447f9d |
531 | =item session_delete_reason |
532 | |
533 | This accessor contains a string with the reason a session was deleted. Possible |
534 | values include: |
535 | |
536 | =over 4 |
537 | |
538 | =item * |
539 | |
540 | C<address mismatch> |
541 | |
542 | =item * |
543 | |
544 | C<session expired> |
545 | |
546 | =back |
547 | |
b7acf64e |
548 | =item session_expire_key $key, $ttl |
549 | |
550 | Mark a key to expire at a certain time (only useful when shorter than the |
551 | expiry time for the whole session). |
552 | |
553 | For example: |
554 | |
555 | __PACKAGE__->config->{session}{expires} = 1000000000000; # forever |
556 | |
557 | # later |
558 | |
559 | $c->session_expire_key( __user => 3600 ); |
560 | |
561 | Will make the session data survive, but the user will still be logged out after |
562 | an hour. |
563 | |
564 | Note that these values are not auto extended. |
565 | |
8f0b4c16 |
566 | =back |
567 | |
10c72079 |
568 | =head1 INTERNAL METHODS |
8f0b4c16 |
569 | |
570 | =over 4 |
571 | |
9e447f9d |
572 | =item setup |
573 | |
574 | This method is extended to also make calls to |
575 | C<check_session_plugin_requirements> and C<setup_session>. |
576 | |
577 | =item check_session_plugin_requirements |
578 | |
579 | This method ensures that a State and a Store plugin are also in use by the |
580 | application. |
581 | |
582 | =item setup_session |
583 | |
584 | This method populates C<< $c->config->{session} >> with the default values |
585 | listed in L</CONFIGURATION>. |
586 | |
587 | =item prepare_action |
588 | |
68fd02ae |
589 | This methoid is extended. |
590 | |
591 | It's only effect is if the (off by default) C<flash_to_stash> configuration |
592 | parameter is on - then it will copy the contents of the flash to the stash at |
593 | prepare time. |
9e447f9d |
594 | |
595 | =item finalize |
596 | |
597 | This method is extended and will extend the expiry time, as well as persist the |
598 | session data if a session exists. |
599 | |
600 | =item delete_session REASON |
601 | |
602 | This method is used to invalidate a session. It takes an optional parameter |
603 | which will be saved in C<session_delete_reason> if provided. |
604 | |
605 | =item initialize_session_data |
606 | |
607 | This method will initialize the internal structure of the session, and is |
608 | called by the C<session> method if appropriate. |
609 | |
68fd02ae |
610 | =item create_session_id |
611 | |
612 | Creates a new session id using C<generate_session_id> if there is no session ID |
613 | yet. |
614 | |
ab634fee |
615 | =item validate_session_id SID |
616 | |
617 | Make sure a session ID is of the right format. |
618 | |
619 | This currently ensures that the session ID string is any amount of case |
620 | insensitive hexadecimal characters. |
621 | |
229a5b53 |
622 | =item generate_session_id |
623 | |
624 | This method will return a string that can be used as a session ID. It is |
625 | supposed to be a reasonably random string with enough bits to prevent |
626 | collision. It basically takes C<session_hash_seed> and hashes it using SHA-1, |
627 | MD5 or SHA-256, depending on the availibility of these modules. |
628 | |
629 | =item session_hash_seed |
630 | |
631 | This method is actually rather internal to generate_session_id, but should be |
632 | overridable in case you want to provide more random data. |
633 | |
634 | Currently it returns a concatenated string which contains: |
635 | |
636 | =over 4 |
637 | |
638 | =item * |
639 | |
640 | A counter |
641 | |
642 | =item * |
643 | |
644 | The current time |
645 | |
646 | =item * |
647 | |
648 | One value from C<rand>. |
649 | |
650 | =item * |
651 | |
652 | The stringified value of a newly allocated hash reference |
653 | |
654 | =item * |
655 | |
656 | The stringified value of the Catalyst context object |
657 | |
658 | =back |
659 | |
660 | In the hopes that those combined values are entropic enough for most uses. If |
661 | this is not the case you can replace C<session_hash_seed> with e.g. |
662 | |
663 | sub session_hash_seed { |
664 | open my $fh, "<", "/dev/random"; |
665 | read $fh, my $bytes, 20; |
666 | close $fh; |
667 | return $bytes; |
668 | } |
669 | |
670 | Or even more directly, replace C<generate_session_id>: |
671 | |
672 | sub generate_session_id { |
673 | open my $fh, "<", "/dev/random"; |
674 | read $fh, my $bytes, 20; |
675 | close $fh; |
676 | return unpack("H*", $bytes); |
677 | } |
678 | |
679 | Also have a look at L<Crypt::Random> and the various openssl bindings - these |
680 | modules provide APIs for cryptographically secure random data. |
681 | |
99b2191e |
682 | =item dump_these |
683 | |
684 | See L<Catalyst/dump_these> - ammends the session data structure to the list of |
685 | dumped objects if session ID is defined. |
686 | |
9e447f9d |
687 | =back |
688 | |
a92c8aeb |
689 | =head1 USING SESSIONS DURING PREPARE |
690 | |
691 | The earliest point in time at which you may use the session data is after |
692 | L<Catalyst::Plugin::Session>'s C<prepare_action> has finished. |
693 | |
694 | State plugins must set $c->session ID before C<prepare_action>, and during |
695 | C<prepare_action> L<Catalyst::Plugin::Session> will actually load the data from |
696 | the store. |
697 | |
698 | sub prepare_action { |
699 | my $c = shift; |
700 | |
701 | # don't touch $c->session yet! |
b1cd7d77 |
702 | |
a92c8aeb |
703 | $c->NEXT::prepare_action( @_ ); |
704 | |
705 | $c->session; # this is OK |
706 | $c->sessionid; # this is also OK |
707 | } |
708 | |
9e447f9d |
709 | =head1 CONFIGURATION |
710 | |
229a5b53 |
711 | $c->config->{session} = { |
712 | expires => 1234, |
713 | }; |
9e447f9d |
714 | |
715 | All configuation parameters are provided in a hash reference under the |
716 | C<session> key in the configuration hash. |
717 | |
718 | =over 4 |
719 | |
720 | =item expires |
721 | |
722 | The time-to-live of each session, expressed in seconds. Defaults to 7200 (two |
723 | hours). |
724 | |
725 | =item verify_address |
726 | |
8c7e922c |
727 | When true, C<<$c->request->address>> will be checked at prepare time. If it is |
728 | not the same as the address that initiated the session, the session is deleted. |
9e447f9d |
729 | |
68fd02ae |
730 | =item flash_to_stash |
731 | |
732 | This option makes it easier to have actions behave the same whether they were |
733 | forwarded to or redirected to. On prepare time it copies the contents of |
734 | C<flash> (if any) to the stash. |
735 | |
9e447f9d |
736 | =back |
737 | |
738 | =head1 SPECIAL KEYS |
739 | |
740 | The hash reference returned by C<< $c->session >> contains several keys which |
741 | are automatically set: |
742 | |
743 | =over 4 |
744 | |
745 | =item __expires |
746 | |
ab634fee |
747 | This key no longer exists. Use C<session_expires> instead. |
9e447f9d |
748 | |
749 | =item __updated |
750 | |
d44bc687 |
751 | The last time a session was saved to the store. |
9e447f9d |
752 | |
753 | =item __created |
754 | |
755 | The time when the session was first created. |
756 | |
757 | =item __address |
758 | |
759 | The value of C<< $c->request->address >> at the time the session was created. |
8c7e922c |
760 | This value is only populated if C<verify_address> is true in the configuration. |
9e447f9d |
761 | |
762 | =back |
763 | |
c80e9f04 |
764 | =head1 CAVEATS |
765 | |
a552e4b5 |
766 | =head2 Round the Robin Proxies |
767 | |
c80e9f04 |
768 | C<verify_address> could make your site inaccessible to users who are behind |
769 | load balanced proxies. Some ISPs may give a different IP to each request by the |
770 | same client due to this type of proxying. If addresses are verified these |
771 | users' sessions cannot persist. |
772 | |
773 | To let these users access your site you can either disable address verification |
774 | as a whole, or provide a checkbox in the login dialog that tells the server |
775 | that it's OK for the address of the client to change. When the server sees that |
776 | this box is checked it should delete the C<__address> sepcial key from the |
777 | session hash when the hash is first created. |
778 | |
a552e4b5 |
779 | =head2 Race Conditions |
780 | |
781 | In this day and age where cleaning detergents and dutch football (not the |
782 | american kind) teams roam the plains in great numbers, requests may happen |
783 | simultaneously. This means that there is some risk of session data being |
784 | overwritten, like this: |
785 | |
786 | =over 4 |
787 | |
788 | =item 1. |
789 | |
790 | request a starts, request b starts, with the same session id |
791 | |
792 | =item 2. |
793 | |
794 | session data is loaded in request a |
795 | |
796 | =item 3. |
797 | |
798 | session data is loaded in request b |
799 | |
800 | =item 4. |
801 | |
802 | session data is changed in request a |
803 | |
804 | =item 5. |
805 | |
806 | request a finishes, session data is updated and written to store |
807 | |
808 | =item 6. |
809 | |
810 | request b finishes, session data is updated and written to store, overwriting |
811 | changes by request a |
812 | |
813 | =back |
814 | |
815 | If this is a concern in your application, a soon to be developed locking |
816 | solution is the only safe way to go. This will have a bigger overhead. |
817 | |
818 | For applications where any given user is only making one request at a time this |
819 | plugin should be safe enough. |
820 | |
d45028d6 |
821 | =head1 AUTHORS |
822 | |
baa9db9c |
823 | =over 4 |
824 | |
825 | =item Andy Grundman |
826 | |
827 | =item Christian Hansen |
828 | |
829 | =item Yuval Kogman, C<nothingmuch@woobling.org> (current maintainer) |
830 | |
831 | =item Sebastian Riedel |
832 | |
833 | =back |
834 | |
835 | And countless other contributers from #catalyst. Thanks guys! |
d45028d6 |
836 | |
cc40ae4b |
837 | =head1 COPYRIGHT & LICENSE |
d45028d6 |
838 | |
839 | Copyright (c) 2005 the aforementioned authors. All rights |
840 | reserved. This program is free software; you can redistribute |
841 | it and/or modify it under the same terms as Perl itself. |
842 | |
9e447f9d |
843 | =cut |
844 | |
845 | |