Mail::SPF::Server(3pm) - phpMan

Mail::SPF::Server(3)  User Contributed Perl Documentation Mail::SPF::Server(3)

NAME
       Mail::SPF::Server - Server class for processing SPF requests
SYNOPSIS
           use Mail::SPF;
           my $spf_server  = Mail::SPF::Server->new(
               # Optional custom default for authority explanation:
               default_authority_explanation =>
                   'See http://www.%{d}/why/id=%{S};ip=%{I};r=%{R}'
           );
           my $result      = $spf_server->process($request);
DESCRIPTION
       Mail::SPF::Server is a server class for processing SPF requests.  Each
       server instance can be configured with specific processing parameters.
       Also, the default Net::DNS::Resolver DNS resolver used for making DNS
       look-ups can be overridden with a custom resolver object.
   Constructor
       The following constructor is provided:
       new(%options): returns Mail::SPF::Server
           Creates a new server object for processing SPF requests.
           %options is a list of key/value pairs representing any of the
           following options:
           default_authority_explanation
               A string denoting the default (not macro-expanded) authority
               explanation string to use if the authority domain does not
               specify an explanation string of its own.  Defaults to:
                   'Please see http://www.openspf.net/Why?s=%{_scope};id=%{S};ip=%{C};r=%{R}'
               As can be seen from the default, a non-standard "_scope" pseudo
               macro is supported that expands to the name of the identity's
               scope.  (Note: Do not use any non-standard macros in
               explanation strings published in DNS.)
           hostname
               A string denoting the local system's fully qualified host name
               that should be used for expanding the "r" macro in explanation
               strings.  Defaults to the system's configured host name.
           dns_resolver
               An optional DNS resolver object.  If none is specified, a new
               Net::DNS::Resolver object is used.  The resolver object may be
               of a different class, but it must provide an interface similar
               to Net::DNS::Resolver -- at least the "send" and "errorstring"
               methods must be supported, and the "send" method must return
               either an object of class Net::DNS::Packet, or, in the case of
               an error, undef.
           query_rr_types
               For which RR types to query when looking up and selecting SPF
               records.  The following values are supported:
               Mail::SPF::Server->query_rr_type_all (default)
                   Both "SPF" and "TXT" type RRs.
               Mail::SPF::Server->query_rr_type_spf
                   "SPF" type RRs only.
               Mail::SPF::Server->query_rr_type_txt
                   "TXT" type RRs only.
               Some (few) name servers suffer from serious brain damage with
               regard to the handling of queries for RR types that are unknown
               to them, such as the "SPF" RR type, so some (few) Mail::SPF
               users have expressed the desire for a way to disable the
               retrieval of "SPF" type RRs.  It is, however, a better idea to
               pressure the manufacturers of such broken name servers into
               fixing their products.
               See RFC 4408, 3.1.1, for a discussion of the topic, as well as
               the description of the "select_record" method.
           max_dns_interactive_terms
               An integer denoting the maximum number of terms (mechanisms and
               modifiers) per SPF check that perform DNS look-ups, as defined
               in RFC 4408, 10.1, paragraph 6.  If undef is specified, there
               is no limit on the number of such terms.  Defaults to 10, which
               is the value defined in RFC 4408.
               A value above the default is strongly discouraged for security
               reasons.  A value below the default has implications with
               regard to the predictability of SPF results.  Only deviate from
               the default if you know what you are doing!
           max_name_lookups_per_term
               An integer denoting the maximum number of DNS name look-ups per
               term (mechanism or modifier), as defined in RFC 4408, 10.1,
               paragraph 7.  If undef is specified, there is no limit on the
               number of look-ups performed.  Defaults to 10, which is the
               value defined in RFC 4408.
               A value above the default is strongly discouraged for security
               reasons.  A value below the default has implications with
               regard to the predictability of SPF results.  Only deviate from
               the default if you know what you are doing!
           max_name_lookups_per_mx_mech
           max_name_lookups_per_ptr_mech
               An integer denoting the maximum number of DNS name look-ups per
               mx or ptr mechanism, respectively.  Defaults to the value of
               the "max_name_lookups_per_term" option.  See there for
               additional information and security notes.
           max_void_dns_lookups
               An integer denoting the maximum number of "void" DNS look-ups
               per SPF check, i.e. the number of DNS look-ups that were caused
               by DNS-interactive terms and macros (as defined in RFC 4408,
               10.1, paragraphs 6 and 7) and that are allowed to return an
               empty answer with RCODE 0 or RCODE 3 ("NXDOMAIN") before
               processing is aborted with a "permerror" result.  If undef is
               specified, there is no stricter limit on the number of void DNS
               look-ups beyond the usual processing limits.  Defaults to 2.
               Specifically, the DNS look-ups that are subject to this limit
               are those caused by the "a", "mx", "ptr", and "exists"
               mechanisms and the "p" macro.
               A value of 2 is likely to prevent effective DoS attacks against
               third-party victim domains.  However, a definite limit may
               cause "permerror" results even with certain (overly complex)
               innocent sender policies where useful results would normally be
               returned.
   Class methods
       The following class methods are provided:
       result_class: returns class
       result_class($name): returns class
           Returns a Mail::SPF::Result descendent class determined from the
           given result name via the server's inherent result base class, or
           returns the server's inherent result base class if no result name
           is given.  This method may also be used as an instance method.
           Note:  Do not write code invoking class methods on literal result
           class names as this would ignore any derivative result classes
           provided by Mail::SPF extension modules.
       throw_result($name, $request): throws Mail::SPF::Result
       throw_result($name, $request, $text): throws Mail::SPF::Result
           Throws a Mail::SPF::Result descendant determined from the given
           result name via the server's inherent result base class, passing an
           optional result text and associating the given Mail::SPF::Request
           object with the result object.  This method may also be used as an
           instance method.
           Note:  Do not write code invoking "throw" on literal result class
           names as this would ignore any derivative result classes provided
           by Mail::SPF extension modules.
   Instance methods
       The following instance methods are provided:
       process($request): returns Mail::SPF::Result
           Processes the given Mail::SPF::Request object, queries the
           authoritative domain for an SPF sender policy (see the description
           of the "select_record" method), evaluates the policy with regard to
           the given identity and other request parameters, and returns a
           Mail::SPF::Result object denoting the result of the policy
           evaluation.  See RFC 4408, 4, and RFC 4406, 4, for details.
       select_record($request): returns Mail::SPF::Record; throws
       Mail::SPF::EDNSError, Mail::SPF::ENoAcceptableRecord,
       Mail::SPF::ERedundantAcceptableRecords, Mail::SPF::ESyntaxError
           Queries the authority domain of the given Mail::SPF::Request object
           for SPF sender policy records and, if multiple records are
           available, selects the record of the highest acceptable record
           version that covers the requested scope.
           More precisely, the following algorithm is performed:
           1.  Determine the authority domain, the set of acceptable SPF
               record versions, and the identity scope from the given request
               object.
           2.  Query the authority domain for SPF records of the "SPF" DNS RR
               type, discarding any records that are of an inacceptable
               version or do not cover the desired scope.
               If this yields no SPF records, query the authority domain for
               SPF records of the "TXT" DNS RR type, discarding any records
               that are of an inacceptable version or do not cover the desired
               scope.
               If still no acceptable SPF records could be found, throw a
               Mail::SPF::ENoAcceptableRecord exception.
           3.  Discard all records but those of the highest acceptable version
               found.
               If exactly one record remains, return it.  Otherwise, throw a
               Mail::SPF::ERedundantAcceptableRecords exception.
           If the querying of either RR type has been disabled via the "new"
           constructor's "query_rr_types" option, the respective part in step
           2 will be skipped.
           Mail::SPF::EDNSError exceptions due to DNS look-ups and
           Mail::SPF::ESyntaxError exceptions due to invalid acceptable
           records may also be thrown.
       get_acceptable_records_from_packet($packet, $rr_type, \@versions,
       $scope, $domain): returns list of Mail::SPF::Record
           Filters from the given Net::DNS::Packet object all resource records
           of the given RR type and for the given domain name, discarding any
           records that are not SPF records at all, that are of an
           inacceptable SPF record version, or that do not cover the given
           scope.  Returns a list of acceptable records.
       dns_lookup($domain, $rr_type): returns Net::DNS::Packet; throws
       Mail::SPF::EDNSTimeout, Mail::SPF::EDNSError
           Queries the DNS using the configured resolver for resource records
           of the desired type at the specified domain and returns a
           Net::DNS::Packet object if an answer packet was received.  Throws a
           Mail::SPF::EDNSTimeout exception if a DNS time-out occurred.
           Throws a Mail::SPF::EDNSError exception if an error (other than
           RCODE 3 AKA "NXDOMAIN") occurred.
       count_dns_interactive_term($request): throws
       Mail::SPF::EProcessingLimitExceeded
           Increments by one the count of DNS-interactive mechanisms and
           modifiers that have been processed so far during the evaluation of
           the given Mail::SPF::Request object.  If this exceeds the
           configured limit (see the "new" constructor's
           "max_dns_interactive_terms" option), throws a
           Mail::SPF::EProcessingLimitExceeded exception.
           This method is supposed to be called by the "match" and "process"
           methods of Mail::SPF::Mech and Mail::SPF::Mod sub-classes before
           (and only if) they do any DNS look-ups.
       count_void_dns_lookup($request): throws
       Mail::SPF::EProcessingLimitExceeded
           Increments by one the count of "void" DNS look-ups that have
           occurred so far during the evaluation of the given
           Mail::SPF::Request object.  If this exceeds the configured limit
           (see the "new" constructor's "max_void_dns_lookups" option), throws
           a Mail::SPF::EProcessingLimitExceeded exception.
           This method is supposed to be called by any code after any calls to
           the "dns_lookup" method whenever (i) no answer records were
           returned, and (ii) this fact is a possible indication of a DoS
           attack against a third-party victim domain, and (iii) the number of
           "void" look-ups is not already constrained otherwise (as for
           example is the case with the "include" mechanism and the "redirect"
           modifier).  Specifically, this applies to look-ups performed by the
           "a", "mx", "ptr", and "exists" mechanisms and the "p" macro.
       default_authority_explanation: returns Mail::SPF::MacroString
           Returns the default authority explanation as a MacroString object.
           See the description of the "new" constructor's
           "default_authority_explanation" option.
       hostname: returns string
           Returns the local system's host name.  See the description of the
           "new" constructor's "hostname" option.
       dns_resolver: returns Net::DNS::Resolver or compatible object
           Returns the DNS resolver object of the server object.  See the
           description of the "new" constructor's "dns_resolver" option.
       query_rr_types: returns integer
           Returns a value denoting the RR types for which to query when
           looking up and selecting SPF records.  See the description of the
           "new" constructor's "query_rr_types" option.
       max_dns_interactive_terms: returns integer
       max_name_lookups_per_term: returns integer
       max_name_lookups_per_mx_mech: returns integer
       max_name_lookups_per_ptr_mech: returns integer
       max_void_dns_lookups: returns integer
           Return the limit values of the server object.  See the description
           of the "new" constructor's corresponding options.
SEE ALSO
       Mail::SPF, Mail::SPF::Request, Mail::SPF::Result
       <http://tools.ietf.org/html/rfc4408>;
       For availability, support, and license information, see the README file
       included with Mail::SPF.
AUTHORS
       Julian Mehnle <julian AT mehnle.net>, Shevek <cpan AT anarres.org>

perl v5.16.3                      2014-06-10              Mail::SPF::Server(3)