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; |
159 | $c->_session_data_sig( |
160 | Object::Signature::signature($session_data) ); |
161 | $c->_expire_session_keys; |
4207ce8d |
162 | |
6687905d |
163 | return $session_data; |
3f182468 |
164 | } |
9a9252c2 |
165 | } |
29d15411 |
166 | |
4207ce8d |
167 | return; |
b7acf64e |
168 | } |
9a9252c2 |
169 | |
9b0fa2a6 |
170 | sub _load_flash { |
171 | my $c = shift; |
172 | |
173 | if ( my $sid = $c->_sessionid ) { |
4207ce8d |
174 | if ( my $flash_data = $c->_flash |
175 | || $c->_flash( $c->get_session_data("flash:$sid") ) ) |
176 | { |
177 | $c->_flash_stale_keys( [ keys %$flash_data ] ); |
9b0fa2a6 |
178 | return $flash_data; |
179 | } |
180 | } |
181 | |
182 | return undef; |
183 | } |
184 | |
d44bc687 |
185 | sub _expire_session_keys { |
b7acf64e |
186 | my ( $c, $data ) = @_; |
187 | |
188 | my $now = time; |
189 | |
4207ce8d |
190 | my $expiry = ( $data || $c->_session || {} )->{__expire_keys} || {}; |
191 | foreach my $key ( grep { $expiry->{$_} < $now } keys %$expiry ) { |
b7acf64e |
192 | delete $c->_session->{$key}; |
193 | delete $expiry->{$key}; |
194 | } |
9e447f9d |
195 | } |
196 | |
197 | sub delete_session { |
9a9252c2 |
198 | my ( $c, $msg ) = @_; |
9e447f9d |
199 | |
9a9252c2 |
200 | # delete the session data |
29d15411 |
201 | my $sid = $c->_sessionid || return; |
4207ce8d |
202 | $c->delete_session_data("${_}:${sid}") for qw/session expires flash/; |
9e447f9d |
203 | |
9a9252c2 |
204 | # reset the values in the context object |
ab634fee |
205 | # see the BEGIN block |
206 | $c->$_(undef) for @session_data_accessors; |
6687905d |
207 | |
29d15411 |
208 | $c->_session_delete_reason($msg); |
209 | } |
210 | |
211 | sub session_delete_reason { |
212 | my $c = shift; |
213 | |
4207ce8d |
214 | $c->_load_session |
215 | if ( $c->_sessionid && !$c->_session ); # must verify session data |
29d15411 |
216 | |
4207ce8d |
217 | $c->_session_delete_reason(@_); |
9e447f9d |
218 | } |
219 | |
6687905d |
220 | sub session_expires { |
221 | my ( $c, $should_create ) = @_; |
222 | |
223 | $c->_session_expires || do { |
224 | if ( my $sid = $c->_sessionid ) { |
225 | my $now = time; |
226 | |
227 | if ( !$should_create ) { |
228 | if ( ( $c->get_session_data("expires:$sid") || 0 ) < $now ) { |
229 | |
230 | # session expired |
231 | $c->log->debug("Deleting session $sid (expired)") |
232 | if $c->debug; |
233 | $c->delete_session("session expired"); |
234 | return 0; |
235 | } |
236 | } |
237 | |
238 | return $c->_session_expires( |
239 | $now + $c->config->{session}{expires} ); |
240 | } |
241 | }; |
242 | } |
243 | |
0974ac06 |
244 | sub sessionid { |
4207ce8d |
245 | my $c = shift; |
246 | |
247 | if (@_) { |
bab8b74b |
248 | if($c->_sessionid()) { |
249 | $c->log->warn('Session ID already set, ignoring.'); |
250 | return $c->_sessionid(); |
251 | } |
4207ce8d |
252 | if ( $c->validate_session_id( my $sid = shift ) ) { |
253 | $c->_sessionid($sid); |
29d15411 |
254 | return unless defined wantarray; |
4207ce8d |
255 | } |
256 | else { |
257 | my $err = "Tried to set invalid session ID '$sid'"; |
258 | $c->log->error($err); |
259 | Catalyst::Exception->throw($err); |
260 | } |
261 | } |
262 | |
263 | $c->_load_session |
264 | if ( $c->_sessionid && !$c->_session ); # must verify session data |
265 | |
266 | return $c->_sessionid; |
0974ac06 |
267 | } |
268 | |
269 | sub validate_session_id { |
4207ce8d |
270 | my ( $c, $sid ) = @_; |
0974ac06 |
271 | |
4207ce8d |
272 | $sid and $sid =~ /^[a-f\d]+$/i; |
0974ac06 |
273 | } |
274 | |
9e447f9d |
275 | sub session { |
9a9252c2 |
276 | my $c = shift; |
9e447f9d |
277 | |
29d15411 |
278 | $c->_session || $c->_load_session || do { |
78476ce0 |
279 | $c->create_session_id; |
9e447f9d |
280 | |
29d15411 |
281 | $c->initialize_session_data; |
4207ce8d |
282 | }; |
9e447f9d |
283 | } |
284 | |
873f7011 |
285 | sub flash { |
286 | my $c = shift; |
78476ce0 |
287 | $c->_flash || $c->_load_flash || do { |
288 | $c->create_session_id; |
289 | $c->_flash( {} ); |
4207ce8d |
290 | } |
873f7011 |
291 | } |
292 | |
b7acf64e |
293 | sub session_expire_key { |
294 | my ( $c, %keys ) = @_; |
295 | |
296 | my $now = time; |
4207ce8d |
297 | @{ $c->session->{__expire_keys} }{ keys %keys } = |
298 | map { $now + $_ } values %keys; |
b7acf64e |
299 | } |
300 | |
9e447f9d |
301 | sub initialize_session_data { |
9a9252c2 |
302 | my $c = shift; |
9e447f9d |
303 | |
9a9252c2 |
304 | my $now = time; |
9e447f9d |
305 | |
4207ce8d |
306 | return $c->_session( |
307 | { |
308 | __created => $now, |
309 | __updated => $now, |
310 | |
311 | ( |
312 | $c->config->{session}{verify_address} |
313 | ? ( __address => $c->request->address ) |
314 | : () |
315 | ), |
316 | } |
317 | ); |
9e447f9d |
318 | } |
319 | |
9e447f9d |
320 | sub generate_session_id { |
321 | my $c = shift; |
322 | |
323 | my $digest = $c->_find_digest(); |
324 | $digest->add( $c->session_hash_seed() ); |
325 | return $digest->hexdigest; |
326 | } |
327 | |
78476ce0 |
328 | sub create_session_id { |
329 | my $c = shift; |
330 | |
331 | if ( !$c->_sessionid ) { |
332 | my $sid = $c->generate_session_id; |
333 | |
334 | $c->log->debug(qq/Created session "$sid"/) if $c->debug; |
335 | |
336 | $c->sessionid($sid); |
6687905d |
337 | $c->session_expires(1); |
78476ce0 |
338 | } |
339 | } |
340 | |
9e447f9d |
341 | my $counter; |
9a9252c2 |
342 | |
9e447f9d |
343 | sub session_hash_seed { |
9a9252c2 |
344 | my $c = shift; |
345 | |
346 | return join( "", ++$counter, time, rand, $$, {}, overload::StrVal($c), ); |
9e447f9d |
347 | } |
348 | |
349 | my $usable; |
9a9252c2 |
350 | |
9e447f9d |
351 | sub _find_digest () { |
9a9252c2 |
352 | unless ($usable) { |
d44bc687 |
353 | foreach my $alg (qw/SHA-1 SHA-256 MD5/) { |
4207ce8d |
354 | if ( eval { Digest->new($alg) } ) { |
5faaa4b0 |
355 | $usable = $alg; |
356 | last; |
357 | } |
7d139eeb |
358 | } |
4207ce8d |
359 | Catalyst::Exception->throw( |
9a9252c2 |
360 | "Could not find a suitable Digest module. Please install " |
4207ce8d |
361 | . "Digest::SHA1, Digest::SHA, or Digest::MD5" ) |
362 | unless $usable; |
9a9252c2 |
363 | } |
9e447f9d |
364 | |
365 | return Digest->new($usable); |
366 | } |
367 | |
99b2191e |
368 | sub dump_these { |
369 | my $c = shift; |
370 | |
371 | ( |
372 | $c->NEXT::dump_these(), |
373 | |
374 | $c->sessionid |
375 | ? ( [ "Session ID" => $c->sessionid ], [ Session => $c->session ], ) |
376 | : () |
377 | ); |
378 | } |
379 | |
9e447f9d |
380 | __PACKAGE__; |
381 | |
382 | __END__ |
383 | |
384 | =pod |
385 | |
386 | =head1 NAME |
387 | |
388 | Catalyst::Plugin::Session - Generic Session plugin - ties together server side |
fb1a4ac3 |
389 | storage and client side state required to maintain session data. |
9e447f9d |
390 | |
391 | =head1 SYNOPSIS |
392 | |
8f0b4c16 |
393 | # To get sessions to "just work", all you need to do is use these plugins: |
394 | |
395 | use Catalyst qw/ |
396 | Session |
397 | Session::Store::FastMmap |
398 | Session::State::Cookie |
399 | /; |
400 | |
401 | # you can replace Store::FastMmap with Store::File - both have sensible |
402 | # default configurations (see their docs for details) |
403 | |
404 | # more complicated backends are available for other scenarios (DBI storage, |
405 | # etc) |
406 | |
407 | |
408 | # after you've loaded the plugins you can save session data |
409 | # For example, if you are writing a shopping cart, it could be implemented |
410 | # like this: |
9e447f9d |
411 | |
229a5b53 |
412 | sub add_item : Local { |
413 | my ( $self, $c ) = @_; |
414 | |
415 | my $item_id = $c->req->param("item"); |
416 | |
8f0b4c16 |
417 | # $c->session is a hash ref, a bit like $c->stash |
418 | # the difference is that it' preserved across requests |
229a5b53 |
419 | |
420 | push @{ $c->session->{items} }, $item_id; |
421 | |
422 | $c->forward("MyView"); |
423 | } |
424 | |
425 | sub display_items : Local { |
426 | my ( $self, $c ) = @_; |
427 | |
428 | # values in $c->session are restored |
429 | $c->stash->{items_to_display} = |
8f0b4c16 |
430 | [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ]; |
229a5b53 |
431 | |
432 | $c->forward("MyView"); |
433 | } |
434 | |
9e447f9d |
435 | =head1 DESCRIPTION |
436 | |
437 | The Session plugin is the base of two related parts of functionality required |
438 | for session management in web applications. |
439 | |
440 | The first part, the State, is getting the browser to repeat back a session key, |
441 | so that the web application can identify the client and logically string |
442 | several requests together into a session. |
443 | |
444 | The second part, the Store, deals with the actual storage of information about |
445 | the client. This data is stored so that the it may be revived for every request |
446 | made by the same client. |
447 | |
448 | This plugin links the two pieces together. |
449 | |
8f0b4c16 |
450 | =head1 RECCOMENDED BACKENDS |
451 | |
452 | =over 4 |
453 | |
454 | =item Session::State::Cookie |
455 | |
456 | The only really sane way to do state is using cookies. |
457 | |
458 | =item Session::Store::File |
459 | |
460 | A portable backend, based on Cache::File. |
461 | |
462 | =item Session::Store::FastMmap |
463 | |
464 | A fast and flexible backend, based on Cache::FastMmap. |
465 | |
466 | =back |
467 | |
9e447f9d |
468 | =head1 METHODS |
469 | |
470 | =over 4 |
471 | |
472 | =item sessionid |
473 | |
474 | An accessor for the session ID value. |
475 | |
476 | =item session |
477 | |
478 | Returns a hash reference that might contain unserialized values from previous |
479 | requests in the same session, and whose modified value will be saved for future |
480 | requests. |
481 | |
482 | This method will automatically create a new session and session ID if none |
483 | exists. |
484 | |
ab634fee |
485 | =item session_expires |
486 | |
487 | =item session_expires $reset |
488 | |
489 | This method returns the time when the current session will expire, or 0 if |
490 | there is no current session. If there is a session and it already expired, it |
491 | will delete the session and return 0 as well. |
492 | |
493 | If the C<$reset> parameter is true, and there is a session ID the expiry time |
494 | will be reset to the current time plus the time to live (see |
495 | L</CONFIGURATION>). This is used when creating a new session. |
496 | |
07e714d2 |
497 | =item flash |
498 | |
499 | This is like Ruby on Rails' flash data structure. Think of it as a stash that |
44ab6d1c |
500 | lasts for longer than one request, letting you redirect instead of forward. |
501 | |
502 | The flash data will be cleaned up only on requests on which actually use |
503 | $c->flash (thus allowing multiple redirections), and the policy is to delete |
504 | all the keys which were present at the time the data was loaded just before the |
505 | data is saved. |
07e714d2 |
506 | |
507 | sub moose : Local { |
508 | my ( $self, $c ) = @_; |
509 | |
510 | $c->flash->{beans} = 10; |
511 | $c->response->redirect( $c->uri_for("foo") ); |
512 | } |
513 | |
514 | sub foo : Local { |
515 | my ( $self, $c ) = @_; |
516 | |
517 | my $value = $c->flash->{beans}; |
518 | |
519 | # ... |
520 | |
521 | $c->response->redirect( $c->uri_for("bar") ); |
522 | } |
523 | |
524 | sub bar : Local { |
525 | my ( $self, $c ) = @_; |
526 | |
527 | if ( exists $c->flash->{beans} ) { # false |
528 | |
529 | } |
530 | } |
531 | |
9e447f9d |
532 | =item session_delete_reason |
533 | |
534 | This accessor contains a string with the reason a session was deleted. Possible |
535 | values include: |
536 | |
537 | =over 4 |
538 | |
539 | =item * |
540 | |
541 | C<address mismatch> |
542 | |
543 | =item * |
544 | |
545 | C<session expired> |
546 | |
547 | =back |
548 | |
b7acf64e |
549 | =item session_expire_key $key, $ttl |
550 | |
551 | Mark a key to expire at a certain time (only useful when shorter than the |
552 | expiry time for the whole session). |
553 | |
554 | For example: |
555 | |
556 | __PACKAGE__->config->{session}{expires} = 1000000000000; # forever |
557 | |
558 | # later |
559 | |
560 | $c->session_expire_key( __user => 3600 ); |
561 | |
562 | Will make the session data survive, but the user will still be logged out after |
563 | an hour. |
564 | |
565 | Note that these values are not auto extended. |
566 | |
8f0b4c16 |
567 | =back |
568 | |
10c72079 |
569 | =head1 INTERNAL METHODS |
8f0b4c16 |
570 | |
571 | =over 4 |
572 | |
9e447f9d |
573 | =item setup |
574 | |
575 | This method is extended to also make calls to |
576 | C<check_session_plugin_requirements> and C<setup_session>. |
577 | |
578 | =item check_session_plugin_requirements |
579 | |
580 | This method ensures that a State and a Store plugin are also in use by the |
581 | application. |
582 | |
583 | =item setup_session |
584 | |
585 | This method populates C<< $c->config->{session} >> with the default values |
586 | listed in L</CONFIGURATION>. |
587 | |
588 | =item prepare_action |
589 | |
68fd02ae |
590 | This methoid is extended. |
591 | |
592 | It's only effect is if the (off by default) C<flash_to_stash> configuration |
593 | parameter is on - then it will copy the contents of the flash to the stash at |
594 | prepare time. |
9e447f9d |
595 | |
596 | =item finalize |
597 | |
598 | This method is extended and will extend the expiry time, as well as persist the |
599 | session data if a session exists. |
600 | |
601 | =item delete_session REASON |
602 | |
603 | This method is used to invalidate a session. It takes an optional parameter |
604 | which will be saved in C<session_delete_reason> if provided. |
605 | |
606 | =item initialize_session_data |
607 | |
608 | This method will initialize the internal structure of the session, and is |
609 | called by the C<session> method if appropriate. |
610 | |
68fd02ae |
611 | =item create_session_id |
612 | |
613 | Creates a new session id using C<generate_session_id> if there is no session ID |
614 | yet. |
615 | |
ab634fee |
616 | =item validate_session_id SID |
617 | |
618 | Make sure a session ID is of the right format. |
619 | |
620 | This currently ensures that the session ID string is any amount of case |
621 | insensitive hexadecimal characters. |
622 | |
229a5b53 |
623 | =item generate_session_id |
624 | |
625 | This method will return a string that can be used as a session ID. It is |
626 | supposed to be a reasonably random string with enough bits to prevent |
627 | collision. It basically takes C<session_hash_seed> and hashes it using SHA-1, |
628 | MD5 or SHA-256, depending on the availibility of these modules. |
629 | |
630 | =item session_hash_seed |
631 | |
632 | This method is actually rather internal to generate_session_id, but should be |
633 | overridable in case you want to provide more random data. |
634 | |
635 | Currently it returns a concatenated string which contains: |
636 | |
637 | =over 4 |
638 | |
639 | =item * |
640 | |
641 | A counter |
642 | |
643 | =item * |
644 | |
645 | The current time |
646 | |
647 | =item * |
648 | |
649 | One value from C<rand>. |
650 | |
651 | =item * |
652 | |
653 | The stringified value of a newly allocated hash reference |
654 | |
655 | =item * |
656 | |
657 | The stringified value of the Catalyst context object |
658 | |
659 | =back |
660 | |
661 | In the hopes that those combined values are entropic enough for most uses. If |
662 | this is not the case you can replace C<session_hash_seed> with e.g. |
663 | |
664 | sub session_hash_seed { |
665 | open my $fh, "<", "/dev/random"; |
666 | read $fh, my $bytes, 20; |
667 | close $fh; |
668 | return $bytes; |
669 | } |
670 | |
671 | Or even more directly, replace C<generate_session_id>: |
672 | |
673 | sub generate_session_id { |
674 | open my $fh, "<", "/dev/random"; |
675 | read $fh, my $bytes, 20; |
676 | close $fh; |
677 | return unpack("H*", $bytes); |
678 | } |
679 | |
680 | Also have a look at L<Crypt::Random> and the various openssl bindings - these |
681 | modules provide APIs for cryptographically secure random data. |
682 | |
99b2191e |
683 | =item dump_these |
684 | |
685 | See L<Catalyst/dump_these> - ammends the session data structure to the list of |
686 | dumped objects if session ID is defined. |
687 | |
9e447f9d |
688 | =back |
689 | |
a92c8aeb |
690 | =head1 USING SESSIONS DURING PREPARE |
691 | |
692 | The earliest point in time at which you may use the session data is after |
693 | L<Catalyst::Plugin::Session>'s C<prepare_action> has finished. |
694 | |
695 | State plugins must set $c->session ID before C<prepare_action>, and during |
696 | C<prepare_action> L<Catalyst::Plugin::Session> will actually load the data from |
697 | the store. |
698 | |
699 | sub prepare_action { |
700 | my $c = shift; |
701 | |
702 | # don't touch $c->session yet! |
b1cd7d77 |
703 | |
a92c8aeb |
704 | $c->NEXT::prepare_action( @_ ); |
705 | |
706 | $c->session; # this is OK |
707 | $c->sessionid; # this is also OK |
708 | } |
709 | |
9e447f9d |
710 | =head1 CONFIGURATION |
711 | |
229a5b53 |
712 | $c->config->{session} = { |
713 | expires => 1234, |
714 | }; |
9e447f9d |
715 | |
716 | All configuation parameters are provided in a hash reference under the |
717 | C<session> key in the configuration hash. |
718 | |
719 | =over 4 |
720 | |
721 | =item expires |
722 | |
723 | The time-to-live of each session, expressed in seconds. Defaults to 7200 (two |
724 | hours). |
725 | |
726 | =item verify_address |
727 | |
8c7e922c |
728 | When true, C<<$c->request->address>> will be checked at prepare time. If it is |
729 | not the same as the address that initiated the session, the session is deleted. |
9e447f9d |
730 | |
68fd02ae |
731 | =item flash_to_stash |
732 | |
733 | This option makes it easier to have actions behave the same whether they were |
734 | forwarded to or redirected to. On prepare time it copies the contents of |
735 | C<flash> (if any) to the stash. |
736 | |
9e447f9d |
737 | =back |
738 | |
739 | =head1 SPECIAL KEYS |
740 | |
741 | The hash reference returned by C<< $c->session >> contains several keys which |
742 | are automatically set: |
743 | |
744 | =over 4 |
745 | |
746 | =item __expires |
747 | |
ab634fee |
748 | This key no longer exists. Use C<session_expires> instead. |
9e447f9d |
749 | |
750 | =item __updated |
751 | |
d44bc687 |
752 | The last time a session was saved to the store. |
9e447f9d |
753 | |
754 | =item __created |
755 | |
756 | The time when the session was first created. |
757 | |
758 | =item __address |
759 | |
760 | The value of C<< $c->request->address >> at the time the session was created. |
8c7e922c |
761 | This value is only populated if C<verify_address> is true in the configuration. |
9e447f9d |
762 | |
763 | =back |
764 | |
c80e9f04 |
765 | =head1 CAVEATS |
766 | |
a552e4b5 |
767 | =head2 Round the Robin Proxies |
768 | |
c80e9f04 |
769 | C<verify_address> could make your site inaccessible to users who are behind |
770 | load balanced proxies. Some ISPs may give a different IP to each request by the |
771 | same client due to this type of proxying. If addresses are verified these |
772 | users' sessions cannot persist. |
773 | |
774 | To let these users access your site you can either disable address verification |
775 | as a whole, or provide a checkbox in the login dialog that tells the server |
776 | that it's OK for the address of the client to change. When the server sees that |
777 | this box is checked it should delete the C<__address> sepcial key from the |
778 | session hash when the hash is first created. |
779 | |
a552e4b5 |
780 | =head2 Race Conditions |
781 | |
782 | In this day and age where cleaning detergents and dutch football (not the |
783 | american kind) teams roam the plains in great numbers, requests may happen |
784 | simultaneously. This means that there is some risk of session data being |
785 | overwritten, like this: |
786 | |
787 | =over 4 |
788 | |
789 | =item 1. |
790 | |
791 | request a starts, request b starts, with the same session id |
792 | |
793 | =item 2. |
794 | |
795 | session data is loaded in request a |
796 | |
797 | =item 3. |
798 | |
799 | session data is loaded in request b |
800 | |
801 | =item 4. |
802 | |
803 | session data is changed in request a |
804 | |
805 | =item 5. |
806 | |
807 | request a finishes, session data is updated and written to store |
808 | |
809 | =item 6. |
810 | |
811 | request b finishes, session data is updated and written to store, overwriting |
812 | changes by request a |
813 | |
814 | =back |
815 | |
816 | If this is a concern in your application, a soon to be developed locking |
817 | solution is the only safe way to go. This will have a bigger overhead. |
818 | |
819 | For applications where any given user is only making one request at a time this |
820 | plugin should be safe enough. |
821 | |
d45028d6 |
822 | =head1 AUTHORS |
823 | |
baa9db9c |
824 | =over 4 |
825 | |
826 | =item Andy Grundman |
827 | |
828 | =item Christian Hansen |
829 | |
830 | =item Yuval Kogman, C<nothingmuch@woobling.org> (current maintainer) |
831 | |
832 | =item Sebastian Riedel |
833 | |
834 | =back |
835 | |
836 | And countless other contributers from #catalyst. Thanks guys! |
d45028d6 |
837 | |
cc40ae4b |
838 | =head1 COPYRIGHT & LICENSE |
d45028d6 |
839 | |
840 | Copyright (c) 2005 the aforementioned authors. All rights |
841 | reserved. This program is free software; you can redistribute |
842 | it and/or modify it under the same terms as Perl itself. |
843 | |
9e447f9d |
844 | =cut |
845 | |
846 | |