Provided by: spamassassin_3.4.2-1_all bug

NAME

       Mail::SpamAssassin::Plugin - SpamAssassin plugin base class

SYNOPSIS

   SpamAssassin configuration:
         loadplugin MyPlugin /path/to/myplugin.pm

   Perl code:
         package MyPlugin;

         use Mail::SpamAssassin::Plugin;
         our @ISA = qw(Mail::SpamAssassin::Plugin);

         sub new {
           my ($class, $mailsa) = @_;

           # the usual perlobj boilerplate to create a subclass object
           $class = ref($class) || $class;
           my $self = $class->SUPER::new($mailsa);
           bless ($self, $class);

           # then register an eval rule, if desired...
           $self->register_eval_rule ("check_for_foo");

           # and return the new plugin object
           return $self;
         }

         ...methods...

         1;

DESCRIPTION

       This is the base class for SpamAssassin plugins; all plugins must be objects that
       implement this class.

       This class provides no-op stub methods for all the callbacks that a plugin can receive.
       It is expected that your plugin will override one or more of these stubs to perform its
       actions.

       SpamAssassin implements a plugin chain; each callback event is passed to each of the
       registered plugin objects in turn.  Any plugin can call
       "$self->inhibit_further_callbacks()" to block delivery of that event to later plugins in
       the chain.  This is useful if the plugin has handled the event, and there will be no need
       for later plugins to handle it as well.

       If you're looking to write a simple eval rule, skip straight to "register_eval_rule()",
       below.

INTERFACE

       In all the plugin APIs below, "options" refers to a reference to a hash containing name-
       value pairs.   This is used to ensure future-compatibility, in that we can add new options
       in future without affecting objects built to an earlier version of the API.

       For example, here would be how to print out the "line" item in a "parse_config()" method:

         sub parse_config {
           my ($self, $opts) = @_;
           print "MyPlugin: parse_config got ".$opts->{line}."\n";
         }

METHODS

       The following methods can be overridden by subclasses to handle events.

       $plugin = MyPluginClass->new ($mailsaobject)
           Constructor.  Plugins that need to register themselves will need to define their own;
           the default super-class constructor will work fine for plugins that just override a
           method.

           Note that subclasses must provide the $mailsaobject to the superclass constructor,
           like so:

             my $self = $class->SUPER::new($mailsaobject);

           Lifecycle note: plugins that will need to store per-scan state should not store that
           on the Plugin object; instead this should be stored on the PerMsgStatus object, see
           "check_start()" below.  It is also likewise recommended that configuration settings be
           stored on the Conf object; see "parse_config()".

       $plugin->parse_config ( { options ... } )
           Parse a configuration line that hasn't already been handled.  "options" is a reference
           to a hash containing these options:

           line
               The line of configuration text to parse.   This has leading and trailing
               whitespace, and comments, removed.

           key The configuration key; ie. the first "word" on the line.

           value
               The configuration value; everything after the first "word" and any whitespace
               after that.

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

           user_config
               A boolean: 1 if reading a user's configuration, 0 if reading the system-wide
               configuration files.

           If the configuration line was a setting that is handled by this plugin, the method
           implementation should call "$self->inhibit_further_callbacks()".

           If the setting is not handled by this plugin, the method should return 0 so that a
           later plugin may handle it, or so that SpamAssassin can output a warning message to
           the user if no plugin understands it.

           Lifecycle note: it is suggested that configuration be stored on the
           "Mail::SpamAssassin::Conf" object in use, instead of the plugin object itself.  That
           can be found as "$plugin->{main}->{conf}", or as "conf" in the $options hash reference
           above.   By storing it on "conf", this allows per-user and system-wide configuration
           precedence to be dealt with correctly.

       $plugin->finish_parsing_start ( { options ... } )
           Signals that the system-wide configuration has been completely read, but internal data
           structures are not yet created. It is possible to use this hook to dynamically change
           the configuration already read in or add new config options.

           "options" is a reference to a hash containing these options:

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

           Note: there are no guarantees that the internal data structures of SpamAssassin will
           not change from release to release.  In particular to this plugin hook, if you modify
           the rules data structures in a third-party plugin, all bets are off until such time
           that an API is present for modifying that configuration data.

       $plugin->finish_parsing_end ( { options ... } )
           Signals that the system-wide configuration parsing has just finished, and SpamAssassin
           is nearly ready to check messages.

           "options" is a reference to a hash containing these options:

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

           Note: there are no guarantees that the internal data structures of SpamAssassin will
           not change from release to release.  In particular to this plugin hook, if you modify
           the rules data structures in a third-party plugin, all bets are off until such time
           that an API is present for modifying that configuration data.

       $plugin->user_conf_parsing_start ( { options ... } )
           Signals that the per-user configuration has been completely read, but not converted to
           internal data structures. It is possible to use this hook to dynamically change the
           configuration already read in or add new config options.

           If "allow_user_rules" is enabled in the configuration, it is possible that additional
           rules have been added since the "finish_parsing_start" plugin hook invocation was
           called.

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

           Note: there are no guarantees that the internal data structures of SpamAssassin will
           not change from release to release.  In particular to this plugin hook, if you modify
           the rules data structures in a third-party plugin, all bets are off until such time
           that an API is present for modifying that configuration data.

       $plugin->user_conf_parsing_end ( { options ... } )
           Signals that the per-user configuration parsing has just finished, and SpamAssassin is
           nearly ready to check messages.   If "allow_user_rules" is enabled in the
           configuration, it is possible that additional rules have been added since the
           "finish_parsing_end" plugin hook invocation was called.

           "options" is a reference to a hash containing these options:

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

           Note: there are no guarantees that the internal data structures of SpamAssassin will
           not change from release to release.  In particular to this plugin hook, if you modify
           the rules data structures in a third-party plugin, all bets are off until such time
           that an API is present for modifying that configuration data.

       $plugin->signal_user_changed ( { options ... } )
           Signals that the current user has changed for a new one.

           username
               The new user's username.

           user_dir
               The new user's home directory. (equivalent to "~".)

           userstate_dir
               The new user's storage directory. (equivalent to "~/.spamassassin".)

       $plugin->services_authorized_for_username ( { options ... } )
           Validates that a given username is authorized to use certain services.

           In order to authorize a user, the plugin should first check that it can handle any of
           the services passed into the method and then set the value for each allowed service to
           true (or any non-negative value).

           The current supported services are: bayessql

           username
               A username

           services
               Reference to a hash containing the services you want to check.

               {

                 'bayessql' => 0

               }

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

       $plugin->compile_now_start ( { options ... } )
           This is called at the beginning of Mail::SpamAssassin::compile_now() so plugins can do
           any necessary initialization for multi-process SpamAssassin (such as spamd or mass-
           check -j).

           use_user_prefs
               The value of $use_user_prefs option in compile_now().

           keep_userstate
               The value of $keep_userstate option in compile_now().

       $plugin->compile_now_finish ( { options ... } )
           This is called at the end of Mail::SpamAssassin::compile_now() so plugins can do any
           necessary initialization for multi-process SpamAssassin (such as spamd or mass-check
           -j).

           use_user_prefs
               The value of $use_user_prefs option in compile_now().

           keep_userstate
               The value of $keep_userstate option in compile_now().

       $plugin->check_start ( { options ... } )
           Signals that a message check operation is starting.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

               Lifecycle note: it is recommended that rules that need to track test state on a
               per-scan basis should store that state on this object, not on the plugin object
               itself, since the plugin object will be shared between all active scanners.

               The message being scanned is accessible through the "$permsgstatus->get_message()"
               API; there are a number of other public APIs on that object, too.  See
               "Mail::SpamAssassin::PerMsgStatus" perldoc.

       $plugin->check_main ( { options ... } )
           Signals that a message should be checked.  Note that implementations of this hook
           should return 1.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->check_tick ( { options ... } )
           Called periodically during a message check operation.  A callback set for this method
           is a good place to run through an event loop dealing with network events triggered in
           a "parse_metadata" method, for example.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->check_post_dnsbl ( { options ... } )
           Called after the DNSBL results have been harvested.  This is a good place to harvest
           your own asynchronously-started network lookups.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->check_post_learn ( { options ... } )
           Called after auto-learning may (or may not) have taken place.  If you wish to perform
           additional learning, whether or not auto-learning happens, this is the place to do it.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->check_end ( { options ... } )
           Signals that a message check operation has just finished, and the results are about to
           be returned to the caller.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.  The current
               score, names of rules that hit, etc. can be retrieved using the public APIs on
               this object.

       $plugin->finish_tests ( { options ... } )
           Called via "Mail::SpamAssassin::finish".  This should clear up any tests that a plugin
           has added to the namespace.

           In certain circumstances, plugins may find it useful to compile perl functions from
           the ruleset, on the fly.  It is important to remove these once the
           "Mail::SpamAssassin" object is deleted, however, and this API allows this.

           Each plugin is responsible for its own generated perl functions.

           conf
               The "Mail::SpamAssassin::Conf" object on which the configuration data should be
               stored.

           See also the "register_generated_rule_method" helper API, below.

       $plugin->extract_metadata ( { options ... } )
           Signals that a message is being mined for metadata.  Some plugins may wish to add
           their own metadata as well.

           msg The "Mail::SpamAssassin::Message" object for this message.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->parsed_metadata ( { options ... } )
           Signals that a message's metadata has been parsed, and can now be accessed by the
           plugin.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->start_rules ( { options ... } )
           Called before testing a set of rules of a given type and priority.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

           ruletype
               The type of the rules about to be performed.

           priority
               The priority level of the rules about to be performed.

       $plugin->hit_rule ( { options ... } )
           Called when a rule fires.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

           ruletype
               The type of the rule that fired.

           rulename
               The name of the rule that fired.

           score
               The rule's score in the active scoreset.

       $plugin->ran_rule ( { options ... } )
           Called after a rule has been tested, whether or not it fired.  When the rule fires,
           the hit_rule callback is always called before this.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

           ruletype
               The type of the rule that was tested.

           rulename
               The name of the rule that was tested.

       $plugin->autolearn_discriminator ( { options ... } )
           Control whether a just-scanned message should be learned as either spam or ham.   This
           method should return one of 1 to learn the message as spam, 0 to learn as ham, or
           "undef" to not learn from the message at all.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->autolearn ( { options ... } )
           Signals that a message is about to be auto-learned as either ham or spam.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

           isspam
               1 if the message is spam, 0 if ham.

       $plugin->per_msg_finish ( { options ... } )
           Signals that a "Mail::SpamAssassin::PerMsgStatus" object is being destroyed, and any
           per-scan context held on that object by this plugin should be destroyed as well.

           Normally, any member variables on the "PerMsgStatus" object will be cleaned up
           automatically -- but if your plugin has made a circular reference on that object, this
           is the place to break them so that garbage collection can operate correctly.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->have_shortcircuited ( { options ... } )
           Has the current scan operation 'short-circuited'?  In other words, can further
           scanning be skipped, since the message is already definitively classified as either
           spam or ham?

           Plugins should return 0 to indicate that scanning should continue, or 1 to indicate
           that short-circuiting has taken effect.

           permsgstatus
               The "Mail::SpamAssassin::PerMsgStatus" context object for this scan.

       $plugin->bayes_learn ( { options ... } )
           Called at the end of a bayes learn operation.

           This phase is the best place to map the raw (original) token value to the SHA1 hashed
           value.

           toksref
               Reference to hash returned by call to tokenize.  The hash takes the format of:

                 {
                   'SHA1 Hash Value' => 'raw (original) value',
                   ...
                 }

               NOTE: This data structure has changed since it was originally introduced in
               version 3.0.0.  The values are no longer perl anonymous hashes, they are a single
               string containing the raw token value.  You can test for backward compatibility by
               checking to see if the value for a key is a reference to a perl HASH, for
               instance:

               if (ref($toksref->{$sometokenkey}) eq 'HASH') {...

               If it is, then you are using the old interface, otherwise you are using the
               current interface.

           isspam
               Boolean value stating what flavor of message the tokens represent, if true then
               message was specified as spam, false is nonspam.  Note, when function is scan then
               isspam value is not valid.

           msgid
               Generated message id of the message just learned.

           msgatime
               Received date of the current message or current time if received date could not be
               determined.  In addition, if the receive date is more than 24 hrs into the future
               it will be reset to current datetime.

       $plugin->bayes_forget ( { options ... } )
           Called at the end of a bayes forget operation.

           toksref
               Reference to hash returned by call to tokenize.  See bayes_learn documentation for
               additional information on the format.

           isspam
               Boolean value stating what flavor of message the tokens represent, if true then
               message was specified as spam, false is nonspam.  Note, when function is scan then
               isspam value is not valid.

           msgid
               Generated message id of the message just forgotten.

       $plugin->bayes_scan ( { options ... } )
           Called at the end of a bayes scan operation.  NOTE: Will not be called in case of
           error or if the message is otherwise skipped.

           toksref
               Reference to hash returned by call to tokenize.  See bayes_learn documentation for
               additional information on the format.

           probsref
               Reference to hash of calculated probabilities for tokens found in the database.

                 {
                   'SHA1 Hash Value' => {
                           'prob' => 'calculated probability',
                           'spam_count' => 'Total number of spam msgs w/ token',
                           'ham_count' => 'Total number of ham msgs w/ token',
                           'atime' => 'Atime value for token in database'
                         }
                 }

           score
               Score calculated for this particular message.

           msgatime
               Calculated atime of the message just learned, note it may have been adjusted if it
               was determined to be too far into the future.

           significant_tokens
               Array ref of the tokens found to be significant in determining the score for this
               message.

       $plugin->plugin_report ( { options ... } )
           Called if the message is to be reported as spam.  If the reporting system is
           available, the variable "$options->{report}->report_available}" should be set to 1; if
           the reporting system successfully reported the message, the variable
           "$options->{report}->report_return}" should be set to 1.

           report
               Reference to the Reporter object ("$options->{report}" in the paragraph above.)

           text
               Reference to a markup removed copy of the message in scalar string format.

           msg Reference to the original message object.

       $plugin->plugin_revoke ( { options ... } )
           Called if the message is to be reported as ham (revokes a spam report). If the
           reporting system is available, the variable "$options->{revoke}->revoke_available}"
           should be set to 1; if the reporting system successfully revoked the message, the
           variable "$options->{revoke}->revoke_return}" should be set to 1.

           revoke
               Reference to the Reporter object ("$options->{revoke}" in the paragraph above.)

           text
               Reference to a markup removed copy of the message in scalar string format.

           msg Reference to the original message object.

       $plugin->whitelist_address( { options ... } )
           Called when a request is made to add an address to a persistent address list.

           address
               Address you wish to add.

           cli_p
               Indicate if the call is being made from a command line interface.

       $plugin->blacklist_address( { options ... } )
           Called when a request is made to add an address to a persistent address list.

           address
               Address you wish to add.

           cli_p
               Indicate if the call is being made from a command line interface.

       $plugin->remove_address( { options ... } )
           Called when a request is made to remove an address to a persistent address list.

           address
               Address you wish to remove.

           cli_p
               Indicate if the call is being made from a command line interface.

       $plugin->spamd_child_init ()
           Called in each new child process when it starts up under spamd.

       $plugin->log_scan_result ( { options ... } )
           Called when spamd has completed scanning a message.  Currently, only spamd calls this
           API.

           result
               The 'result: ...' line for this scan.  Format is as described at
               http://wiki.apache.org/spamassassin/SpamdSyslogFormat.

       $plugin->spamd_child_post_connection_close ()
           Called when child returns from handling a connection.

           If there was an accept failure, the child will die and this code will not be called.

       $plugin->finish ()
           Called when the "Mail::SpamAssassin" object is destroyed.

       $plugin->learner_new ()
           Used to support human-trained probabilistic classifiers like the BAYES_* ruleset.
           Called when a new "Mail::SpamAssassin::Bayes" object has been created; typically when
           a new user's scan is about to start.

       $plugin->learn_message ()
           Train the classifier with a training message.

           isspam
               1 if the message is spam, 0 if it's non-spam.

           msg The message's "Mail::SpamAssassin::Message" object.

           id  An optional message-identification string, used internally to tag the message.  If
               it is "undef", one will be generated.  It should be unique to that message.

       $plugin->forget_message ()
           Tell the classifier to 'forget' its training about a specific message.

           msg The message's "Mail::SpamAssassin::Message" object.

           id  An optional message-identification string, used internally to tag the message.  If
               it is "undef", one will be generated.  It should be unique to that message.

       $plugin->learner_sync ()
           Tell the classifier to 'sync' any pending changes against the current user's training
           database.  This is called by "sa-learn --sync".

           If you do not need to implement these for your classifier, create an implementation
           that just contains "return 1".

       $plugin->learner_expire_old_training ()
           Tell the classifier to perform infrequent, time-consuming cleanup of the current
           user's training database.  This is called by "sa-learn --force-expire".

           If you do not need to implement these for your classifier, create an implementation
           that just contains "return 1".

       $plugin->learner_is_scan_available ()
           Should return 1 if it is possible to use the current user's training data for a
           message-scan operation, or 0 otherwise.

       $plugin->learner_dump_database ()
           Dump information about the current user's training data to "stdout".  This is called
           by "sa-learn --dump".

           magic
               Set to 1 if "magic" name-value metadata should be dumped.

           toks
               Set to 1 if the database of tokens should be dumped.

           regex
               Either "undef" to dump all tokens, or a value which specifies a regular expression
               subset of the tokens to dump.

       $plugin->learner_close ()
           Close any open databases.

           quiet
               Set to 1 if warning messages should be suppressed.

HELPER APIS

       These methods provide an API for plugins to register themselves to receive specific
       events, or control the callback chain behaviour.

       $plugin->register_eval_rule ($nameofevalsub)
           Plugins that implement an eval test will need to call this, so that SpamAssassin calls
           into the object when that eval test is encountered.  See the REGISTERING EVAL RULES
           section for full details.

       $plugin->register_generated_rule_method ($nameofsub)
           In certain circumstances, plugins may find it useful to compile perl functions from
           the ruleset, on the fly.  It is important to remove these once the
           "Mail::SpamAssassin" object is deleted, however, and this API allows this.

           Once the method $nameofsub has been generated, call this API with the name of the
           method (including full package scope).  This indicates that it's a temporary piece of
           generated code, built from the SpamAssassin ruleset, and when
           "Mail::SpamAssassin::finish()" is called, the method will be destroyed.

           This API was added in SpamAssassin 3.2.0.

       $plugin->register_method_priority($methodname, $priority)
           Indicate that the method named $methodname on the current object has a callback
           priority of $priority.

           This is used by the plugin handler to determine the relative order of callbacks;
           plugins with lower-numbered priorities are called before plugins with higher-numbered
           priorities.  Each method can have a different priority value.  The default value is 0.
           The ordering of callbacks to methods with equal priority is undefined.

           Typically, you only need to worry about this if you need to ensure your plugin's
           method is called before another plugin's implementation of that method.  It should be
           called from your plugin's constructor.

           This API was added in SpamAssassin 3.2.0.

       $plugin->inhibit_further_callbacks()
           Tells the plugin handler to inhibit calling into other plugins in the plugin chain for
           the current callback.  Frequently used when parsing configuration settings using
           "parse_config()".

LOGGING

       Mail::SpamAssassin::Plugin::dbg($message)
           Output a debugging message $message, if the SpamAssassin object is running with
           debugging turned on.

           NOTE: This function is not available in the package namespace of general plugins and
           can't be called via $self->dbg().  If a plugin wishes to output debug information, it
           should call "Mail::SpamAssassin::Plugin::dbg($msg)".

       Mail::SpamAssassin::Plugin::info($message)
           Output an informational message $message, if the SpamAssassin object is running with
           informational messages turned on.

           NOTE: This function is not available in the package namespace of general plugins and
           can't be called via $self->info().  If a plugin wishes to output debug information, it
           should call "Mail::SpamAssassin::Plugin::info($msg)".

           In general, it is better for plugins to use the "Mail::SpamAssassin::Logger" module to
           import "dbg" and "info" directly, like so:

             use Mail::SpamAssassin::Logger;
             dbg("some message");
             info("some other message");

REGISTERING EVAL RULES

       Plugins that implement an eval test must register the methods that can be called from
       rules in the configuration files, in the plugin class' constructor.

       For example,

         $plugin->register_eval_rule ('check_for_foo')

       will cause "$plugin->check_for_foo()" to be called for this SpamAssassin rule:

         header   FOO_RULE     eval:check_for_foo()

       Note that eval rules are passed the following arguments:

       - The plugin object itself
       - The "Mail::SpamAssassin::PerMsgStatus" object calling the rule
       - standard arguments for the rule type in use
       - any and all arguments as specified in the configuration file

       In other words, the eval test method should look something like this:

         sub check_for_foo {
           my ($self, $permsgstatus, ...arguments...) = @_;
           ...code returning 0 or 1
         }

       Note that the headers can be accessed using the "get()" method on the
       "Mail::SpamAssassin::PerMsgStatus" object, and the body by
       "get_decoded_stripped_body_text_array()" and other similar methods.  Similarly, the
       "Mail::SpamAssassin::Conf" object holding the current configuration may be accessed
       through "$permsgstatus->{main}->{conf}".

       The eval rule should return 1 for a hit, or 0 if the rule is not hit.

       State for a single message being scanned should be stored on the $permsgstatus object, not
       on the $self object, since $self persists between scan operations.  See the 'lifecycle
       note' on the "check_start()" method above.

STANDARD ARGUMENTS FOR RULE TYPES

       Plugins will be called with the same arguments as a standard EvalTest.  Different rule
       types receive different information by default:

       - header tests: no extra arguments
       - body tests: fully rendered message as array reference
       - rawbody tests: fully decoded message as array reference
       - full tests: pristine message as scalar reference

       The configuration file arguments will be passed in after the standard arguments.

BACKWARD COMPATIBILITY

       Note that if you write a plugin and need to determine if a particular helper method is
       supported on "Mail::SpamAssassin::Plugin", you can do this:

           if ($self->can("name_of_method")) {
             eval {
               $self->name_of_method();        # etc.
             }
           } else {
             # take fallback action
           }

       The same applies for the public APIs on objects of other types, such as
       "Mail::SpamAssassin::PerMsgStatus".

SEE ALSO

       "Mail::SpamAssassin"

       "Mail::SpamAssassin::PerMsgStatus"

       http://wiki.apache.org/spamassassin/PluginWritingTips

       http://issues.apache.org/SpamAssassin/show_bug.cgi?id=2163