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jà¸ ©‹FÿÆ„ã?a–ß=¿J	µ2ÛR‚ œP!¸Û—˜´oÅ '³    # Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""DNS Dynamic Update Support"""

import dns.message
import dns.name
import dns.opcode
import dns.rdata
import dns.rdataclass
import dns.rdataset
import dns.tsig

class Update(dns.message.Message):
    def __init__(self, zone, rdclass=dns.rdataclass.IN, keyring=None,
                 keyname=None, keyalgorithm=dns.tsig.default_algorithm):
        """Initialize a new DNS Update object.

        @param zone: The zone which is being updated.
        @type zone: A dns.name.Name or string
        @param rdclass: The class of the zone; defaults to dns.rdataclass.IN.
        @type rdclass: An int designating the class, or a string whose value
        is the name of a class.
        @param keyring: The TSIG keyring to use; defaults to None.
        @type keyring: dict
        @param keyname: The name of the TSIG key to use; defaults to None.
        The key must be defined in the keyring.  If a keyring is specified
        but a keyname is not, then the key used will be the first key in the
        keyring.  Note that the order of keys in a dictionary is not defined,
        so applications should supply a keyname when a keyring is used, unless
        they know the keyring contains only one key.
        @type keyname: dns.name.Name or string
        @param keyalgorithm: The TSIG algorithm to use; defaults to
        dns.tsig.default_algorithm.  Constants for TSIG algorithms are defined
        in dns.tsig, and the currently implemented algorithms are
        HMAC_MD5, HMAC_SHA1, HMAC_SHA224, HMAC_SHA256, HMAC_SHA384, and
        HMAC_SHA512.
        @type keyalgorithm: string
        """
        super(Update, self).__init__()
        self.flags |= dns.opcode.to_flags(dns.opcode.UPDATE)
        if isinstance(zone, (str, unicode)):
            zone = dns.name.from_text(zone)
        self.origin = zone
        if isinstance(rdclass, str):
            rdclass = dns.rdataclass.from_text(rdclass)
        self.zone_rdclass = rdclass
        self.find_rrset(self.question, self.origin, rdclass, dns.rdatatype.SOA,
                        create=True, force_unique=True)
        if not keyring is None:
            self.use_tsig(keyring, keyname, algorithm=keyalgorithm)

    def _add_rr(self, name, ttl, rd, deleting=None, section=None):
        """Add a single RR to the update section."""

        if section is None:
            section = self.authority
        covers = rd.covers()
        rrset = self.find_rrset(section, name, self.zone_rdclass, rd.rdtype,
                                covers, deleting, True, True)
        rrset.add(rd, ttl)

    def _add(self, replace, section, name, *args):
        """Add records.  The first argument is the replace mode.  If
        false, RRs are added to an existing RRset; if true, the RRset
        is replaced with the specified contents.  The second
        argument is the section to add to.  The third argument
        is always a name.  The other arguments can be:

                - rdataset...

                - ttl, rdata...

                - ttl, rdtype, string..."""

        if isinstance(name, (str, unicode)):
            name = dns.name.from_text(name, None)
        if isinstance(args[0], dns.rdataset