Python dns.flags() Examples

def _make_dns_message(self, zone_name, notify=False):
        """
        This constructs a SOA query or a dns NOTIFY message.
        :param zone_name: The zone name for which a SOA/NOTIFY needs to be
            sent.
        :param notify: If true, a notify message is constructed else a SOA
            message is constructed.
        :return: The constructed message.
        """
        dns_message = dns.message.make_query(zone_name, dns.rdatatype.SOA)
        dns_message.flags = 0
        if notify:
            dns_message.set_opcode(dns.opcode.NOTIFY)
            dns_message.flags |= dns.flags.AA
        else:
            # Setting the flags to RD causes BIND9 to respond with a NXDOMAIN.
            dns_message.set_opcode(dns.opcode.QUERY)
            dns_message.flags |= dns.flags.RD

        return dns_message 

def reset(self):
        """Reset all resolver configuration to the defaults."""
        self.domain = \
            dns.name.Name(dns.name.from_text(socket.gethostname())[1:])
        if len(self.domain) == 0:
            self.domain = dns.name.root
        self.nameservers = []
        self.nameserver_ports = {}
        self.port = 53
        self.search = []
        self.timeout = 2.0
        self.lifetime = 30.0
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = dns.tsig.default_algorithm
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.cache = None
        self.flags = None
        self.retry_servfail = False
        self.rotate = False 

def reset(self):
        """Reset all resolver configuration to the defaults."""
        self.domain = \
            dns.name.Name(dns.name.from_text(socket.gethostname())[1:])
        if len(self.domain) == 0:
            self.domain = dns.name.root
        self.nameservers = []
        self.nameserver_ports = {}
        self.port = 53
        self.search = []
        self.timeout = 2.0
        self.lifetime = 30.0
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = dns.tsig.default_algorithm
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.cache = None
        self.flags = None
        self.retry_servfail = False
        self.rotate = False 

def read(self):
        """Read a wire format DNS message and build a dns.message.Message
        object."""

        l = len(self.wire)
        if l < 12:
            raise ShortHeader
        (self.message.id, self.message.flags, qcount, ancount,
         aucount, adcount) = struct.unpack('!HHHHHH', self.wire[:12])
        self.current = 12
        if dns.opcode.is_update(self.message.flags):
            self.updating = True
        self._get_question(qcount)
        if self.question_only:
            return
        self._get_section(self.message.answer, ancount)
        self._get_section(self.message.authority, aucount)
        self._get_section(self.message.additional, adcount)
        if not self.ignore_trailing and self.current != l:
            raise TrailingJunk
        if self.message.multi and self.message.tsig_ctx and \
                not self.message.had_tsig:
            self.message.tsig_ctx.update(self.wire) 

def is_response(self, other):
        """Is other a response to self?
        @rtype: bool"""
        if other.flags & dns.flags.QR == 0 or \
           self.id != other.id or \
           dns.opcode.from_flags(self.flags) != \
           dns.opcode.from_flags(other.flags):
            return False
        if dns.rcode.from_flags(other.flags, other.ednsflags) != \
                dns.rcode.NOERROR:
            return True
        if dns.opcode.is_update(self.flags):
            return True
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        return True 

def read(self):
        """Read a wire format DNS message and build a dns.message.Message
        object."""

        l = len(self.wire)
        if l < 12:
            raise ShortHeader
        (self.message.id, self.message.flags, qcount, ancount,
         aucount, adcount) = struct.unpack('!HHHHHH', self.wire[:12])
        self.current = 12
        if dns.opcode.is_update(self.message.flags):
            self.updating = True
        self._get_question(qcount)
        if self.question_only:
            return
        self._get_section(self.message.answer, ancount)
        self._get_section(self.message.authority, aucount)
        self._get_section(self.message.additional, adcount)
        if not self.ignore_trailing and self.current != l:
            raise TrailingJunk
        if self.message.multi and self.message.tsig_ctx and \
                not self.message.had_tsig:
            self.message.tsig_ctx.update(self.wire) 

def read(self):
        """Read a wire format DNS message and build a dns.message.Message
        object."""

        l = len(self.wire)
        if l < 12:
            raise ShortHeader
        (self.message.id, self.message.flags, qcount, ancount,
         aucount, adcount) = struct.unpack('!HHHHHH', self.wire[:12])
        self.current = 12
        if dns.opcode.is_update(self.message.flags):
            self.updating = True
        self._get_question(qcount)
        if self.question_only:
            return
        self._get_section(self.message.answer, ancount)
        self._get_section(self.message.authority, aucount)
        self._get_section(self.message.additional, adcount)
        if not self.ignore_trailing and self.current != l:
            raise TrailingJunk
        if self.message.multi and self.message.tsig_ctx and \
                not self.message.had_tsig:
            self.message.tsig_ctx.update(self.wire) 

def reset(self):
        """Reset all resolver configuration to the defaults."""
        self.domain = \
            dns.name.Name(dns.name.from_text(socket.gethostname())[1:])
        if len(self.domain) == 0:
            self.domain = dns.name.root
        self.nameservers = []
        self.nameserver_ports = {}
        self.port = 53
        self.search = []
        self.timeout = 2.0
        self.lifetime = 30.0
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = dns.tsig.default_algorithm
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.cache = None
        self.flags = None
        self.retry_servfail = False
        self.rotate = False 

def is_response(self, other):
        """Is other a response to self?
        @rtype: bool"""
        if other.flags & dns.flags.QR == 0 or \
           self.id != other.id or \
           dns.opcode.from_flags(self.flags) != \
           dns.opcode.from_flags(other.flags):
            return False
        if dns.rcode.from_flags(other.flags, other.ednsflags) != \
                dns.rcode.NOERROR:
            return True
        if dns.opcode.is_update(self.flags):
            return True
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        return True 

def is_response(self, other):
        """Is other a response to self?
        @rtype: bool"""
        if other.flags & dns.flags.QR == 0 or \
           self.id != other.id or \
           dns.opcode.from_flags(self.flags) != \
           dns.opcode.from_flags(other.flags):
            return False
        if dns.rcode.from_flags(other.flags, other.ednsflags) != \
               dns.rcode.NOERROR:
            return True
        if dns.opcode.is_update(self.flags):
            return True
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        return True 

def reset(self):
        """Reset all resolver configuration to the defaults."""
        self.domain = \
            dns.name.Name(dns.name.from_text(socket.gethostname())[1:])
        if len(self.domain) == 0:
            self.domain = dns.name.root
        self.nameservers = []
        self.search = []
        self.port = 53
        self.timeout = 2.0
        self.lifetime = 30.0
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = dns.tsig.default_algorithm
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.cache = None
        self.flags = None
        self.retry_servfail = False 

def is_response(self, other):
        """Is other a response to self?
        @rtype: bool"""
        if other.flags & dns.flags.QR == 0 or \
           self.id != other.id or \
           dns.opcode.from_flags(self.flags) != \
           dns.opcode.from_flags(other.flags):
            return False
        if dns.rcode.from_flags(other.flags, other.ednsflags) != \
                dns.rcode.NOERROR:
            return True
        if dns.opcode.is_update(self.flags):
            return True
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        return True 

def is_response(self, other):
        """Is other a response to self?
        @rtype: bool"""
        if other.flags & dns.flags.QR == 0 or \
           self.id != other.id or \
           dns.opcode.from_flags(self.flags) != \
           dns.opcode.from_flags(other.flags):
            return False
        if dns.rcode.from_flags(other.flags, other.ednsflags) != \
                dns.rcode.NOERROR:
            return True
        if dns.opcode.is_update(self.flags):
            return True
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        return True 

def read(self):
        """Read a wire format DNS message and build a dns.message.Message
        object."""

        l = len(self.wire)
        if l < 12:
            raise ShortHeader
        (self.message.id, self.message.flags, qcount, ancount,
         aucount, adcount) = struct.unpack('!HHHHHH', self.wire[:12])
        self.current = 12
        if dns.opcode.is_update(self.message.flags):
            self.updating = True
        self._get_question(qcount)
        if self.question_only:
            return
        self._get_section(self.message.answer, ancount)
        self._get_section(self.message.authority, aucount)
        self._get_section(self.message.additional, adcount)
        if not self.ignore_trailing and self.current != l:
            raise TrailingJunk
        if self.message.multi and self.message.tsig_ctx and \
               not self.message.had_tsig:
            self.message.tsig_ctx.update(self.wire) 

def query_ds(target, ns, timeout=5.0):
    """
    Function for performing DS Record queries. Returns answer object. Since a
    timeout will break the DS NSEC chain of a zone walk it will exit if a timeout
    happens.
    """
    try:
        query = dns.message.make_query(target, dns.rdatatype.DS, dns.rdataclass.IN)
        query.flags += dns.flags.CD
        query.use_edns(edns=True, payload=4096)
        query.want_dnssec(True)
        answer = dns.query.udp(query, ns, timeout)
    except dns.exception.Timeout:
        print_error("A timeout error occurred please make sure you can reach the target DNS Servers")
        print_error(
            "directly and requests are not being filtered. Increase the timeout from {0} second".format(timeout))
        print_error("to a higher number with --lifetime <time> option.")
        sys.exit(1)
    except:
        print("Unexpected error: {0}".format(sys.exc_info()[0]))
        raise
    return answer 

def check_recursive(ns_server, timeout):
    """
    Check if a NS Server is recursive.
    """
    is_recursive = False
    query = dns.message.make_query('www.google.com.', dns.rdatatype.NS)
    try:
        response = dns.query.udp(query, ns_server, timeout)
        recursion_flag_pattern = "\.*RA\.*"
        flags = dns.flags.to_text(response.flags)
        result = re.findall(recursion_flag_pattern, flags)
        if (result):
            print_error("\t Recursion enabled on NS Server {0}".format(ns_server))
        is_recursive = True
    except (socket.error, dns.exception.Timeout):
        return is_recursive
    return is_recursive 

def set_rcode(self, rcode):
        """Set the rcode.
        @param rcode: the rcode
        @type rcode: int
        """
        (value, evalue) = dns.rcode.to_flags(rcode)
        self.flags &= 0xFFF0
        self.flags |= value
        self.ednsflags &= long(0x00FFFFFF)
        self.ednsflags |= evalue
        if self.ednsflags != 0 and self.edns < 0:
            self.edns = 0 

def __init__(self, filename='/etc/resolv.conf', configure=True):
        """Initialize a resolver instance.

        @param filename: The filename of a configuration file in
        standard /etc/resolv.conf format.  This parameter is meaningful
        only when I{configure} is true and the platform is POSIX.
        @type filename: string or file object
        @param configure: If True (the default), the resolver instance
        is configured in the normal fashion for the operating system
        the resolver is running on.  (I.e. a /etc/resolv.conf file on
        POSIX systems and from the registry on Windows systems.)
        @type configure: bool"""

        self.domain = None
        self.nameservers = None
        self.nameserver_ports = None
        self.port = None
        self.search = None
        self.timeout = None
        self.lifetime = None
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = None
        self.edns = None
        self.ednsflags = None
        self.payload = None
        self.cache = None
        self.flags = None
        self.retry_servfail = False
        self.rotate = False

        self.reset()
        if configure:
            if sys.platform == 'win32':
                self.read_registry()
            elif filename:
                self.read_resolv_conf(filename) 

def use_edns(self, edns, ednsflags, payload):
        """Configure Edns.

        @param edns: The EDNS level to use.  The default is -1, no Edns.
        @type edns: int
        @param ednsflags: The EDNS flags
        @type ednsflags: int
        @param payload: The EDNS payload size.  The default is 0.
        @type payload: int"""

        if edns is None:
            edns = -1
        self.edns = edns
        self.ednsflags = ednsflags
        self.payload = payload 

def opcode(self):
        """Return the opcode.
        @rtype: int
        """
        return dns.opcode.from_flags(self.flags) 

def __init__(self, id=None):
        if id is None:
            self.id = dns.entropy.random_16()
        else:
            self.id = id
        self.flags = 0
        self.question = []
        self.answer = []
        self.authority = []
        self.additional = []
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.options = []
        self.request_payload = 0
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = dns.tsig.default_algorithm
        self.request_mac = ''
        self.other_data = ''
        self.tsig_error = 0
        self.fudge = 300
        self.original_id = self.id
        self.mac = ''
        self.xfr = False
        self.origin = None
        self.tsig_ctx = None
        self.had_tsig = False
        self.multi = False
        self.first = True
        self.index = {} 

def _getnameinfo(sockaddr, flags=0):
    host = sockaddr[0]
    port = sockaddr[1]
    if len(sockaddr) == 4:
        scope = sockaddr[3]
        family = socket.AF_INET6
    else:
        scope = None
        family = socket.AF_INET
    tuples = _getaddrinfo(host, port, family, socket.SOCK_STREAM,
                          socket.SOL_TCP, 0)
    if len(tuples) > 1:
        raise socket.error('sockaddr resolved to multiple addresses')
    addr = tuples[0][4][0]
    if flags & socket.NI_DGRAM:
        pname = 'udp'
    else:
        pname = 'tcp'
    qname = dns.reversename.from_address(addr)
    if flags & socket.NI_NUMERICHOST == 0:
        try:
            answer = _resolver.query(qname, 'PTR')
            hostname = answer.rrset[0].target.to_text(True)
        except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
            if flags & socket.NI_NAMEREQD:
                raise socket.gaierror(socket.EAI_NONAME)
            hostname = addr
            if scope is not None:
                hostname += '%' + str(scope)
    else:
        hostname = addr
        if scope is not None:
            hostname += '%' + str(scope)
    if flags & socket.NI_NUMERICSERV:
        service = str(port)
    else:
        service = socket.getservbyport(port, pname)
    return (hostname, service) 

def __eq__(self, other):
        """Two messages are equal if they have the same content in the
        header, question, answer, and authority sections.
        @rtype: bool"""
        if not isinstance(other, Message):
            return False
        if self.id != other.id:
            return False
        if self.flags != other.flags:
            return False
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        for n in self.answer:
            if n not in other.answer:
                return False
        for n in other.answer:
            if n not in self.answer:
                return False
        for n in self.authority:
            if n not in other.authority:
                return False
        for n in other.authority:
            if n not in self.authority:
                return False
        return True 

def set_opcode(self, opcode):
        """Set the opcode.
        @param opcode: the opcode
        @type opcode: int
        """
        self.flags &= 0x87FF
        self.flags |= dns.opcode.to_flags(opcode) 

def __eq__(self, other):
        """Two messages are equal if they have the same content in the
        header, question, answer, and authority sections.
        @rtype: bool"""
        if not isinstance(other, Message):
            return False
        if self.id != other.id:
            return False
        if self.flags != other.flags:
            return False
        for n in self.question:
            if n not in other.question:
                return False
        for n in other.question:
            if n not in self.question:
                return False
        for n in self.answer:
            if n not in other.answer:
                return False
        for n in other.answer:
            if n not in self.answer:
                return False
        for n in self.authority:
            if n not in other.authority:
                return False
        for n in other.authority:
            if n not in self.authority:
                return False
        return True 

def make_response(query, recursion_available=False, our_payload=8192,
                  fudge=300):
    """Make a message which is a response for the specified query.
    The message returned is really a response skeleton; it has all
    of the infrastructure required of a response, but none of the
    content.

    The response's question section is a shallow copy of the query's
    question section, so the query's question RRsets should not be
    changed.

    @param query: the query to respond to
    @type query: dns.message.Message object
    @param recursion_available: should RA be set in the response?
    @type recursion_available: bool
    @param our_payload: payload size to advertise in EDNS responses; default
    is 8192.
    @type our_payload: int
    @param fudge: TSIG time fudge; default is 300 seconds.
    @type fudge: int
    @rtype: dns.message.Message object"""

    if query.flags & dns.flags.QR:
        raise dns.exception.FormError('specified query message is not a query')
    response = dns.message.Message(query.id)
    response.flags = dns.flags.QR | (query.flags & dns.flags.RD)
    if recursion_available:
        response.flags |= dns.flags.RA
    response.set_opcode(query.opcode())
    response.question = list(query.question)
    if query.edns >= 0:
        response.use_edns(0, 0, our_payload, query.payload)
    if query.had_tsig:
        response.use_tsig(query.keyring, query.keyname, fudge, None, 0, '',
                          query.keyalgorithm)
        response.request_mac = query.mac
    return response 

def __init__(self, id=None):
        if id is None:
            self.id = dns.entropy.random_16()
        else:
            self.id = id
        self.flags = 0
        self.question = []
        self.answer = []
        self.authority = []
        self.additional = []
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.options = []
        self.request_payload = 0
        self.keyring = None
        self.keyname = None
        self.keyalgorithm = dns.tsig.default_algorithm
        self.request_mac = ''
        self.other_data = ''
        self.tsig_error = 0
        self.fudge = 300
        self.original_id = self.id
        self.mac = ''
        self.xfr = False
        self.origin = None
        self.tsig_ctx = None
        self.had_tsig = False
        self.multi = False
        self.first = True
        self.index = {} 

def make_response(query, recursion_available=False, our_payload=8192):
    """Make a message which is a response for the specified query.
    The message returned is really a response skeleton; it has all
    of the infrastructure required of a response, but none of the
    content.

    The response's question section is a shallow copy of the query's
    question section, so the query's question RRsets should not be
    changed.

    @param query: the query to respond to
    @type query: dns.message.Message object
    @param recursion_available: should RA be set in the response?
    @type recursion_available: bool
    @param our_payload: payload size to advertise in EDNS responses; default
    is 8192.
    @type our_payload: int
    @rtype: dns.message.Message object"""

    if query.flags & dns.flags.QR:
        raise dns.exception.FormError('specified query message is not a query')
    response = dns.message.Message(query.id)
    response.flags = dns.flags.QR | (query.flags & dns.flags.RD)
    if recursion_available:
        response.flags |= dns.flags.RA
    response.set_opcode(query.opcode())
    response.question = list(query.question)
    if query.edns >= 0:
        response.use_edns(0, 0, our_payload, query.payload)
    if not query.keyname is None:
        response.keyname = query.keyname
        response.keyring = query.keyring
        response.request_mac = query.mac
    return response 

def _getnameinfo(sockaddr, flags=0):
    host = sockaddr[0]
    port = sockaddr[1]
    if len(sockaddr) == 4:
        scope = sockaddr[3]
        family = socket.AF_INET6
    else:
        scope = None
        family = socket.AF_INET
    tuples = _getaddrinfo(host, port, family, socket.SOCK_STREAM,
                          socket.SOL_TCP, 0)
    if len(tuples) > 1:
        raise socket.error('sockaddr resolved to multiple addresses')
    addr = tuples[0][4][0]
    if flags & socket.NI_DGRAM:
        pname = 'udp'
    else:
        pname = 'tcp'
    qname = dns.reversename.from_address(addr)
    if flags & socket.NI_NUMERICHOST == 0:
        try:
            answer = _resolver.query(qname, 'PTR')
            hostname = answer.rrset[0].target.to_text(True)
        except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
            if flags & socket.NI_NAMEREQD:
                raise socket.gaierror(socket.EAI_NONAME)
            hostname = addr
            if scope is not None:
                hostname += '%' + str(scope)
    else:
        hostname = addr
        if scope is not None:
            hostname += '%' + str(scope)
    if flags & socket.NI_NUMERICSERV:
        service = str(port)
    else:
        service = socket.getservbyport(port, pname)
    return (hostname, service) 

def use_edns(self, edns, ednsflags, payload):
        """Configure Edns.

        @param edns: The EDNS level to use.  The default is -1, no Edns.
        @type edns: int
        @param ednsflags: The EDNS flags
        @type ednsflags: int
        @param payload: The EDNS payload size.  The default is 0.
        @type payload: int"""

        if edns is None:
            edns = -1
        self.edns = edns
        self.ednsflags = ednsflags
        self.payload = payload