Module state, per query.

This class provides these data attributes:

.. attribute:: qinfo

    (:class:`query_info`) Informations about query being answered. Name, RR type, RR class.

.. attribute:: query_flags

    (uint16) Flags for query. See QF_BIT\_ predefined constants.

.. attribute:: is_priming

    If this is a (stub or root) priming query (with hints).

.. attribute:: reply

    comm_reply contains server replies.

.. attribute:: return_msg

    (:class:`dns_msg`) The reply message, with message for client and calling module (read-only attribute).
    Note that if you want to create of modify return_msg you should use :class:`DNSMessage`.

.. attribute:: return_rcode

    The rcode, in case of error, instead of a reply message. Determines whether the return_msg contains reply.

.. attribute:: region

    Region for this query. Cleared when query process finishes.

.. attribute:: curmod

    Which module is executing.

.. attribute:: ext_state[]

    Module states.

.. attribute:: env

    Environment for this query.

.. attribute:: mesh_info

    Mesh related information for this query.

.. attribute:: edns_opts_front_in

    Incoming EDNS options from the front end.

.. attribute:: edns_opts_front_in_iter

    Iterator for `edns_opts_front_in`.

.. attribute:: edns_opts_back_out

    Outgoing EDNS options to the back end.

.. attribute:: edns_opts_back_out_iter

    Iterator for `edns_opts_back_out`.

.. attribute:: edns_opts_back_in

    Incoming EDNS options from the back end.

.. attribute:: edns_opts_back_in_iter

    Iterator for `ends_opts_back_in`.

.. attribute:: edns_opts_front_out

    Outgoing EDNS options to the front end.

.. attribute:: edns_opts_front_out_iter

    Iterator for `edns_opts_front_out`.

.. attribute:: no_cache_lookup

    Flag to indicate whether modules should answer from the cache.

.. attribute:: no_cache_store

    Flag to indicate whether modules should store answer in the cache.

This class provides these data attributes:

.. attribute:: qname

   The original question in the wireformat format (e.g. \\x03www\\x03nic\\x02cz\\x00 for www.nic.cz)

.. attribute:: qname_len

   Length of question name (number of bytes).

.. attribute:: qname_list[]

   The question ``qname`` converted into list of labels (e.g. ['www','nic','cz',''] for www.nic.cz)

.. attribute:: qname_str

   The question ``qname`` converted into string (e.g. www.nic.cz. for www.nic.cz)

.. attribute:: qtype

   The class type asked for. See RR_TYPE\_ predefined constants.

.. attribute:: qtype_str

   The ``qtype`` in display presentation format (string) (e.g 'A' for RR_TYPE_A)

.. attribute:: qclass

   The question class. See RR_CLASS\_ predefined constants.

.. attribute:: qclass_str

   The ``qclass`` in display presentation format (string).

This class represents the EDNS information parsed/encoded from/to a packet. It provides these data attributes:

.. attribute:: edns_present

    If EDNS OPT record is present.

.. attribute:: ext_rcode

    Extended RCODE.

.. attribute:: edns_version

    The EDNS version number.

.. attribute:: bits

    The EDNS bits field from ttl (host order): Z.

.. attribute:: udp_size

    UDP reassembly size.

.. attribute:: opt_list

    The EDNS option list.

.. attribute:: opt_list_iter

    Iterator for `opt_list`.

This class represents an EDNS option (code, data) found in EDNS option lists. It provides these data attributes:

.. attribute:: code

The EDNS option code.

.. attribute:: data

The EDNS option data.

This class provides these data attributes:

.. attribute:: flags

   The flags for the answer, host byte order.

.. attribute:: qdcount

   Number of RRs in the query section.
   If qdcount is not 0, then it is 1, and the data that appears
   in the reply is the same as the query_info.
   Host byte order.

.. attribute:: ttl

   TTL of the entire reply (for negative caching).
   only for use when there are 0 RRsets in this message.
   if there are RRsets, check those instead.

.. attribute:: security

   The security status from DNSSEC validation of this message. See sec_status\_ predefined constants.

.. attribute:: an_numrrsets

   Number of RRsets in each section.
   The answer section. Add up the RRs in every RRset to calculate
   the number of RRs, and the count for the dns packet.
   The number of RRs in RRsets can change due to RRset updates.

.. attribute:: ns_numrrsets

   Count of authority section RRsets

.. attribute:: ar_numrrsets

   Count of additional section RRsets

.. attribute:: rrset_count

   Number of RRsets: an_numrrsets + ns_numrrsets + ar_numrrsets

.. attribute:: rrsets[]

      (:class:`ub_packed_rrset_key`) List of RR sets in the order in which they appear in the reply message.
      Number of elements is ancount + nscount + arcount RRsets.

.. attribute:: ref[]

      (:class:`rrset_ref`) Packed array of ids (see counts) and pointers to packed_rrset_key.
      The number equals ancount + nscount + arcount RRsets.
      These are sorted in ascending pointer, the locking order. So
      this list can be locked (and id, ttl checked), to see if
      all the data is available and recent enough.

Region allocated message reply

This class provides these data attributes:

.. attribute:: qinfo

   (:class:`query_info`) Informations about query.

.. attribute:: rep

   (:class:`reply_info`) This attribute points to the packed reply structure.

The identifying information for an RRset.

This class provides these data attributes:

.. attribute:: dname

   The domain name. If not empty (for ``id = None``) it is allocated, and
   contains the wireformat domain name. This dname is not canonicalized.
   E.g., the dname contains \\x03www\\x03nic\\x02cz\\x00 for www.nic.cz.

.. attribute:: dname_len

   Length of the domain name, including last 0 root octet.

.. attribute:: dname_list[]

   The domain name ``dname`` converted into list of labels (see :attr:`query_info.qname_list`).

.. attribute:: dname_str

   The domain name ``dname`` converted into string (see :attr:`query_info.qname_str`).

.. attribute:: flags

   Flags.

.. attribute:: type

   The rrset type in network format.

.. attribute:: type_str

   The rrset type in display presentation format.

.. attribute:: rrset_class

   The rrset class in network format.

.. attribute:: rrset_class_str

   The rrset class in display presentation format.

This structure contains an RRset. A set of resource records that share the same domain name, type and class. Due to memory management and threading, the key structure cannot be deleted, although the data can be. The id can be set to 0 to store and the structure can be recycled with a new id.

The :class:`ub_packed_rrset_key` provides these data attributes:

.. attribute:: entry

   (:class:`lruhash_entry`) Entry into hashtable. Note the lock is never destroyed,
   even when this key is retired to the cache.
   the data pointer (if not None) points to a :class:`packed_rrset`.

.. attribute:: id

   The ID of this rrset. unique, based on threadid + sequenceno.
   ids are not reused, except after flushing the cache.
   zero is an unused entry, and never a valid id.
   Check this value after getting entry.lock.
   The other values in this struct may only be altered after changing
   the id (which needs a writelock on entry.lock).

.. attribute:: rk

   (:class:`packed_rrset_key`) RR set data.

The :class:`ub_packed_rrset_key` provides these data attributes:

.. attribute:: lock

   rwlock for access to the contents of the entry. Note that you cannot change hash and key, if so, you have to delete it to change hash or key.

.. attribute:: data

   (:class:`packed_rrset_data`) entry data stored in wireformat (RRs and RRsigs).

Rdata is stored in wireformat. The dname is stored in wireformat.

TTLs are stored as absolute values (and could be expired).

RRSIGs are stored in the arrays after the regular rrs.

You need the packed_rrset_key to know dname, type, class of the resource records in this RRset. (if signed the rrsig gives the type too).

The :class:`packed_rrset_data` provides these data attributes:

.. attribute:: ttl

   TTL (in seconds like time()) of the RRset.
   Same for all RRs see rfc2181(5.2).

.. attribute:: count

   Number of RRs.

.. attribute:: rrsig_count

   Number of rrsigs, if 0 no rrsigs.

.. attribute:: trust

   The trustworthiness of the RRset data.

.. attribute:: security

   Security status of the RRset data. See sec_status\_ predefined constants.

.. attribute:: rr_len[]

   Length of every RR's rdata, rr_len[i] is size of rr_data[i].

.. attribute:: rr_ttl[]

   TTL of every rr. rr_ttl[i] ttl of rr i.

.. attribute:: rr_data[]

   Array of RR's rdata (list of strings). The rdata is stored in uncompressed wireformat.
   The first 16B of rr_data[i] is rdlength in network format.

Abstract representation of DNS message.

Usage

This example shows how to create an authoritative answer response

msg = DNSMessage(qstate.qinfo.qname_str, RR_TYPE_A, RR_CLASS_IN, PKT_AA)

#append RR
if (qstate.qinfo.qtype == RR_TYPE_A) or (qstate.qinfo.qtype == RR_TYPE_ANY):
    msg.answer.append("%s 10 IN A 127.0.0.1" % qstate.qinfo.qname_str)

#set qstate.return_msg
if not msg.set_return_msg(qstate):
    raise Exception("Can't create response")

The :class:`DNSMessage` provides these methods and data attributes:

.. method:: __init__(self, rr_name, rr_type, rr_class = RR_CLASS_IN, query_flags = 0, default_ttl = 0)

   Prepares an answer (DNS packet) from given information. Query flags are combination of PKT_xx constants.

.. method:: set_return_msg(self, qstate)

   This method fills qstate return message according to the given informations.
             It takes lists of RRs in each section of answer, created necessary RRsets in wire format and store the result in :attr:`qstate.return_msg`.
             Returns 1 if OK.

.. attribute:: rr_name

   RR name of question.

.. attribute:: rr_type

   RR type of question.

.. attribute:: rr_class

   RR class of question.

.. attribute:: default_ttl

   Default time-to-live.

.. attribute:: query_flags

   Query flags. See PKT\_ predefined constants.

.. attribute:: question[]

   List of resource records that should appear (in the same order) in question section of answer.

.. attribute:: answer[]

   List of resource records that should appear (in the same order) in answer section of answer.

.. attribute:: authority[]

   List of resource records that should appear (in the same order) in authority section of answer.

.. attribute:: additional[]

   List of resource records that should appear (in the same order) in additional section of answer.

Global state for the module.

This class provides these data attributes:

.. attribute:: data

   Here you can keep your own data shared across each thread.

.. attribute:: fname

     Python script filename.

.. attribute:: qstate

   Module query state.

Per query state for the iterator module.

This class provides these data attributes:

.. attribute:: data

        Here you can keep your own private data (each thread has own data object).

The :class:`sockaddr_storage` provides these data attributes:

.. attribute:: family

   Address family name as a string. Possible values are `ip4`, `ip6`, and `unix`.

.. attribute:: addr

   Address in presentation format.

.. attribute:: raw_addr

   Address in network wire format.

.. attribute:: port

   Port number. Invalid for Unix address.

.. attribute:: flowinfo

   Flow info value. Valid only for IPv6 address.

.. attribute:: scope_id

   Scope ID value. Valid only for IPv6 address.