NAME

       Mail::SPF::Util - Mail::SPF utility class

SYNOPSIS

           use Mail::SPF::Util;

           $hostname = Mail::SPF::Util->hostname;

           $ipv6_address_v4mapped =
               Mail::SPF::Util->ipv4_address_to_ipv6($ipv4_address);

           $ipv4_address =
               Mail::SPF::Util->ipv6_address_to_ipv4($ipv6_address_v4mapped);

           $is_v4mapped =
               Mail::SPF::Util->ipv6_address_is_ipv4_mapped($ipv6_address);

           $ip_address_string  = Mail::SPF::Util->ip_address_to_string($ip_address);
           $reverse_name       = Mail::SPF::Util->ip_address_reverse($ip_address);

           $validated_domain = Mail::SPF::Util->valid_domain_for_ip_address(
               $spf_server, $request,
               $ip_address, $domain,
               $find_best_match,       # defaults to false
               $accept_any_domain      # defaults to false
           );

           $sanitized_string = Mail::SPF::Util->sanitize_string($string);

DESCRIPTION

       Mail::SPF::Util is Mail::SPF's utility class.

   Class methods
       The following class methods are provided:

       hostname: returns string
           Returns the fully qualified domain name (FQDN) of the local host.

       ipv4_address_to_ipv6($ipv4_address): returns NetAddr::IP; throws
       Mail::SPF::EInvalidOptionValue
           Converts the specified NetAddr::IP IPv4 address into an IPv4-mapped IPv6 address.
           Throws a Mail::SPF::EInvalidOptionValue exception if the specified IP address is not
           an IPv4 address.

       ipv6_address_to_ipv4($ipv6_address): returns NetAddr::IP; throws
       Mail::SPF::EInvalidOptionValue
           Converts the specified NetAddr::IP IPv4-mapped IPv6 address into a proper IPv4
           address.  Throws a Mail::SPF::EInvalidOptionValue exception if the specified IP
           address is not an IPv4-mapped IPv6 address.

       ipv6_address_is_ipv4_mapped($ipv6_address): returns boolean
           Returns true if the specified NetAddr::IP IPv6 address is an IPv4-mapped address,
           false otherwise.

       ip_address_to_string($ip_address): returns string; throws Mail::SPF::EInvalidOptionValue
           Returns the given NetAddr::IP IPv4 or IPv6 address compactly formatted as a string.
           For IPv4 addresses, this is equivalent to calling NetAddr::IP's "addr" method.  For
           IPv6 addresses, this is equivalent to calling NetAddr::IP's "short" method.  Throws a
           Mail::SPF::EInvalidOptionValue exception if the specified object is not a NetAddr::IP
           IPv4 or IPv6 address object.

       ip_address_reverse($ip_address): returns string; throws Mail::SPF::EInvalidOptionValue
           Returns the "in-addr.arpa."/"ip6.arpa." reverse notation of the given NetAddr::IP IPv4
           or IPv6 address.  Throws a Mail::SPF::EInvalidOptionValue exception if the specified
           object is not a NetAddr::IP IPv4 or IPv6 address object.

       valid_domain_for_ip_address($server, $request, $ip_address, $domain, $find_best_match =
       false, $accept_any_domain = false): returns string or undef
           Finds a valid domain name for the given NetAddr::IP IP address that matches the given
           domain or a sub-domain thereof.  A domain name is valid for the given IP address if
           the IP address reverse-maps to that domain name in DNS, and the domain name in turn
           forward-maps to the IP address.  Uses the given Mail::SPF::Server and
           Mail::SPF::Request objects to perform DNS look-ups.  Returns the validated domain
           name.

           If $find_best_match is true, the one domain name is selected that best matches the
           given domain name, preferring direct matches over sub-domain matches.  Defaults to
           false.

           If $accept_any_domain is true, any domain names are considered acceptable, even if
           they differ completely from the given domain name (which is then effectively unused
           unless a best match is requested).  Defaults to false.

       sanitize_string($string): returns string or undef
           Replaces all non-printable or non-ascii characters in a string with their hex-escaped
           representation (e.g., "\x00").

SEE ALSO

       Mail::SPF

       For availability, support, and license information, see the README file included with
       Mail::SPF.

AUTHORS

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