Ubuntu Manpage: Mail::SPF::Mod - SPF record modifier base class

Provided by: libmail-spf-perl_2.9.0-4_all

NAME

       Mail::SPF::Mod - SPF record modifier base class

DESCRIPTION

       An object of class Mail::SPF::Mod represents a modifier within an SPF record.
       Mail::SPF::Mod cannot be instantiated directly.  Create an instance of a concrete sub-
       class instead.

   Constructors
       The following constructors are provided:

       new(%options): returns Mail::SPF::Mod
           Abstract.  Creates a new SPF record modifier object.

           %options is a list of key/value pairs representing any of the following options:

           text
               A string denoting the unparsed text of the modifier.

           name
               A string denoting the name of the modifier.  Required if a generic Mail::SPF::Mod
               object (as opposed to a specific sub-class) is being constructed.

           domain_spec
               Either a plain string or a Mail::SPF::MacroString object denoting an optional
               "domain-spec" parameter of the mechanism.

       new_from_string($text, %options): returns Mail::SPF::Mod; throws
       Mail::SPF::ENothingToParse, Mail::SPF::EInvalidMod
           Abstract.  Creates a new SPF record modifier object by parsing the string and any
           options given.

   Class methods
       The following class methods are provided:

       name_pattern: returns Regexp
           Returns a regular expression that matches any legal modifier name.

   Instance methods
       The following instance methods are provided:

       text: returns string; throws Mail::SPF::ENoUnparsedText
           Returns the unparsed text of the modifier.  Throws a Mail::SPF::ENoUnparsedText
           exception if the modifier was created synthetically instead of being parsed, and no
           text was provided.

       name: returns string
           Returns the name of the modifier.

       params: returns string
           Abstract.  Returns the modifier's parameters formatted as a string.

           A sub-class of Mail::SPF::Mod does not have to implement this method if it supports no
           parameters, although this is highly unlikely.

       stringify: returns string
           Formats the modifier's name and parameters as a string and returns it.  You can simply
           use a Mail::SPF::Mod object as a string for the same effect, see "OVERLOADING".

       process: throws Mail::SPF::Result, Mail::SPF::Result::Error, Mail::SPF::Exception
           Abstract.  Processes the modifier.  What that means depends on the actual
           implementation in sub-classes.  See "MODIFIER TYPES" below.

           This method is abstract and must be implemented by sub-classes of Mail::SPF::Mod.

MODIFIER TYPES

There are different basic types of modifiers, which are described below. All of them are
provided by the Mail::SPF::Mod module.

Global modifiers - Mail::SPF::GlobalMod
SPFv1 (RFC 4408) only knows "global" modifiers. A global modifier may appear anywhere in
an SPF record, but only once. During evaluation of the record, global modifiers are
processed after the last mechanism has been evaluated and an SPF result has been
determined.

The following additional class method is provided by Mail::SPF::GlobalMod:

precedence: returns real
Abstract. Returns a real number between 0 and 1 denoting the precedence of the type
of the global modifier. Global modifiers present in an SPF record are processed in
the order of their precedence values, 0 meaning "first".

This method is abstract and must be implemented by sub-classes of
Mail::SPF::GlobalMod.

The following specific instance method is provided by Mail::SPF::GlobalMod:

process($server, $request, $result): throws Mail::SPF::Result
Abstract. Processes the modifier. What that means depends on the actual
implementation in sub-classes. Takes both a Mail::SPF::Server and a
Mail::SPF::Request object. As global modifiers are generally processed after an SPF
result has already been determined, takes also the current Mail::SPF::Result. If the
modifier wishes to modify the SPF result, it may throw a different Mail::SPF::Result
object.

This method is abstract and must be implemented by sub-classes of
Mail::SPF::GlobalMod.

Positional modifiers - Mail::SPF::PositionalMod
Sender ID (RFC 4406) introduces the concept of "positional" modifiers. According to RFC
4406, a positional modifier must follow a mechanism and applies to that, and only that,
mechanism. However, because this definition is not very useful, and because no positional
modifiers have been defined based on it as of yet, Mail::SPF deviates from RFC 4406 as
follows:

A positional modifier may appear anywhere in an SPF record, and it is stateful, i.e. it
applies to all mechanisms and modifiers that follow it. Positional modifiers are
generally multiple, i.e. they may appear any number of times throughout the record.
During evaluation of the record, positional modifiers are processed at exactly the time
when they are encountered by the evaluator. Consequently, all positional modifiers are
processed before an SPF result is determined.

The following specific instance method is provided by Mail::SPF::PositionalMod:

process($server, $request): throws Mail::SPF::Result::Error, Mail::SPF::Exception
Abstract. Processes the modifier. What that means depends on the actual
implementation in sub-classes. Takes both a Mail::SPF::Server and a
Mail::SPF::Request object. As global modifiers are generally processed before an SPF
result has been determined, no result object is available to the modifier. The
modifier can (at least at this time) not directly modify the final SPF result, however
it may throw an exception to signal an error condition.

This method is abstract and must be implemented by sub-classes of
Mail::SPF::PositionalMod.

Unknown modifiers - Mail::SPF::UnknownMod
Both SPFv1 and Sender ID allow unknown modifiers to appear in SPF records in order to
allow new modifiers to be introduced without breaking existing implementations.
Obviously, unknown modifiers are neither global nor positional, but they may appear any
number of times throughout the record and are simply ignored during evaluation of the
record.

Also obviously, Mail::SPF::UnknownMod does not support a "process" method.

The following specific instance method is provided by Mail::SPF::UnknownMod:

params: returns string
Returns the modifier's unparsed value as a string.

OVERLOADING

       If a Mail::SPF::Mod object is used as a string, the "stringify" method is used to convert
       the object into a string.

AUTHORS

       Julian Mehnle <julian@mehnle.net>, Shevek <cpan@anarres.org>

NAME

DESCRIPTION

MODIFIER TYPES

OVERLOADING

SEE ALSO

AUTHORS