Mail::SpamAssassin::Plugin(3)
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
that SpamAssassin will call back to:
$plugin = MyPluginClass->new ($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; 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}".
This allows per-user and system-wide configuration to be dealt with
correctly, with per-user overriding system-wide.
$plugin->finish_parsing_end ( { options ... } )
Signals that the 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->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 SpamAssassin::finish and 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.
$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 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.
$plugin->bayes_learn ( { options ... } )
Called at the end of a bayes learn operation.
This phase is the best place to map the raw (original) token
value to the SHA1 hashed value.
toksref
Reference to hash returned by call to tokenize. The hash
takes the format of:
{
'SHA1 Hash Value' => 'raw (original) value'
}
NOTE: This data structure has changed since it was
originally introduced in version 3.0.0. The values are no
longer perl anonymous hashes, they are a single string
containing the raw token value. You can test for backwards
compatability by checking to see if the value for a key is
a reference to a perl HASH, for instance:
if (ref($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-<gt"{report}-><gt>report_available}> should be set to
1; if the reporting system successfully reported the message,
the variable "$options-<gt"{report}-><gt>report_return}> should
be set to 1.
report
Reference to the Reporter object ("$options-<gt"{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-<gt"{revoke}-><gt>revoke_available}> should be set to
1; if the reporting system successfully revoked the message,
the variable "$options-<gt"{revoke}-><gt>revoke_return}> should
be set to 1.
revoke
Reference to the Reporter object ("$options-<gt"{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.
$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.
$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.
$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.
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.
$plugin->inhibit_further_callbacks()
Tells the plugin handler to inhibit calling into other plugins in
the plugin chain for the current callback. Frequently used when
parsing configuration settings using "parse_config()".
dbg($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)".
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)".
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
$checker 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(3)
Mail::SpamAssassin::PerMsgStatus(3)
http://wiki.apache.org/spamassassin/PluginWritingTips
http://issues.apache.org/SpamAssassin/show_bug.cgi?id=2163
POD ERRORS
Hey! The above document had some coding errors, which are explained
below:
Around line 826:
You forgot a '=back' before '=head1'
perl v5.10.0 2007-06-19 Mail::SpamAssassin::Plugin(3)
Mac OS X 10.6Server - Generated Thu Apr 15 06:47:05 CDT 2010