Mail::SpamAssassin::PlUser(Contributed Perl DocumMail::SpamAssassin::Plugin(3)NAMEMail::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 "regis‐
ter_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-compati‐
bility, 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 super‐
class 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()".
$plugin->parse_config ( { options ... } )
Parse a configuration line that hasn't already been handled.
"options" is a reference to a hash containing these options:
line
The line of configuration text to parse. This has leading and
trailing whitespace, and comments, removed.
key The configuration key; ie. the first "word" on the line.
value
The configuration value; everything after the first "word" and
any whitespace after that.
conf
The "Mail::SpamAssassin::Conf" object on which the configura‐
tion data should be stored.
user_config
A boolean: 1 if reading a user's configuration, 0 if reading
the system-wide configuration files.
If the configuration line was a setting that is handled by this
plugin, the method implementation should call "$self->inhibit_fur‐
ther_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 SpamAs‐
sassin can output a warning message to the user if no plugin under‐
stands 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 prece‐
dence 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 pos‐
sible 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 configura‐
tion data should be stored.
Note: there are no guarantees that the internal data structures of
SpamAssassin will not change from release to release. In particu‐
lar 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 fin‐
ished, 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 configura‐
tion data should be stored.
Note: there are no guarantees that the internal data structures of
SpamAssassin will not change from release to release. In particu‐
lar 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 possi‐
ble that additional rules have been added since the "finish_pars‐
ing_start" plugin hook invocation was called.
conf
The "Mail::SpamAssassin::Conf" object on which the configura‐
tion data should be stored.
Note: there are no guarantees that the internal data structures of
SpamAssassin will not change from release to release. In particu‐
lar 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_pars‐
ing_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 configura‐
tion data should be stored.
Note: there are no guarantees that the internal data structures of
SpamAssassin will not change from release to release. In particu‐
lar 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 "~/.spamassas‐
sin".)
$plugin->services_authorized_for_username ( { options ... } )
Validates that a given username is authorized to use certain ser‐
vices.
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 configura‐
tion data should be stored.
$plugin->compile_now_start ( { options ... } )
This is called at the beginning of Mail::SpamAssassin::com‐
pile_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 Spa‐
mAssassin (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().
$plugin->check_start ( { options ... } )
Signals that a message check operation is starting.
permsgstatus
The "Mail::SpamAssassin::PerMsgStatus" context object for this
scan.
Lifecycle note: it is recommended that rules that need to track
test state on a per-scan basis should store that state on this
object, not on the plugin object itself, since the plugin
object will be shared between all active scanners.
The message being scanned is accessible through the "$perms‐
gstatus->get_message()" API; there are a number of other public
APIs on that object, too. See "Mail::SpamAssassin::PerMsgSta‐
tus" perldoc.
$plugin->check_main ( { options ... } )
Signals that a message should be checked. Note that implementa‐
tions 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-learn‐
ing 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, how‐
ever, and this API allows this.
Each plugin is responsible for its own generated perl functions.
conf
The "Mail::SpamAssassin::Conf" object on which the configura‐
tion 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.
$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 mes‐
sage 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.
$plugin->bayes_learn ( { options ... } )
Called at the end of a bayes learn operation.
This phase is the best place to map the raw (original) token value
to the SHA1 hashed value.
toksref
Reference to hash returned by call to tokenize. The hash takes
the format of:
{
'SHA1 Hash Value' => 'raw (original) value',
...
}
NOTE: This data structure has changed since it was originally
introduced in version 3.0.0. The values are no longer perl
anonymous hashes, they are a single string containing the raw
token value. You can test for backwards compatibility by
checking to see if the value for a key is a reference to a perl
HASH, for instance:
if (ref($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 repre‐
sent, if true then message was specified as spam, false is non‐
spam. 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 repre‐
sent, if true then message was specified as spam, false is non‐
spam. 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 inter‐
face.
$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 inter‐
face.
$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 inter‐
face.
$plugin->spamd_child_init ()
Called when a new child 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 mes‐
sage.
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 cur‐
rent 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 train‐
ing data for a message-scan operation, or 0 otherwise.
$plugin->learner_dump_database ()
Dump information about the current user's training data to "std‐
out". 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 encoun‐
tered. 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, how‐
ever, 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 indi‐
cates 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 implementa‐
tion of that method. It should be called from your plugin's con‐
structor.
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 $self->dbg(). If a plugin
wishes to output debug information, it should call "Mail::SpamAs‐
sassin::Plugin::dbg($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 $self->info(). If a plugin
wishes to output debug information, it should call "Mail::SpamAs‐
sassin::Plugin::info($msg)".
In general, it is better for plugins to use the "Mail::SpamAssas‐
sin::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 SpamAssas‐
sin 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 $self persists
between scan operations. See the 'lifecycle note' on the
"check_start()" method above.
STANDARD ARGUMENTS FOR RULE TYPES
Plugins will be called with the same arguments as a standard EvalTest.
Different rule types receive different information by default:
- header tests: no extra arguments
- body tests: fully rendered message as array reference
- rawbody tests: fully decoded message as array reference
- full tests: pristine message as scalar reference
The configuration file arguments will be passed in after the standard
arguments.
BACKWARDS COMPATIBILITY
Note that if you write a plugin and need to determine if a particular
helper method is supported on "Mail::SpamAssassin::Plugin", you can do
this:
if ($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
perl v5.8.8 2010-03-16 Mail::SpamAssassin::Plugin(3)
