Source code for dns.update

# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license

# 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"""

from typing import Any, List, Optional, Union

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


class UpdateSection(dns.enum.IntEnum):
    """Update sections"""

    ZONE = 0
    PREREQ = 1
    UPDATE = 2
    ADDITIONAL = 3

    @classmethod
    def _maximum(cls):
        return 3


[docs] class UpdateMessage(dns.message.Message): # lgtm[py/missing-equals] # ignore the mypy error here as we mean to use a different enum _section_enum = UpdateSection # type: ignore def __init__( self, zone: Optional[Union[dns.name.Name, str]] = None, rdclass: dns.rdataclass.RdataClass = dns.rdataclass.IN, keyring: Optional[Any] = None, keyname: Optional[dns.name.Name] = None, keyalgorithm: Union[dns.name.Name, str] = dns.tsig.default_algorithm, id: Optional[int] = None, ): """Initialize a new DNS Update object. See the documentation of the Message class for a complete description of the keyring dictionary. *zone*, a ``dns.name.Name``, ``str``, or ``None``, the zone which is being updated. ``None`` should only be used by dnspython's message constructors, as a zone is required for the convenience methods like ``add()``, ``replace()``, etc. *rdclass*, an ``int`` or ``str``, the class of the zone. The *keyring*, *keyname*, and *keyalgorithm* parameters are passed to ``use_tsig()``; see its documentation for details. """ super().__init__(id=id) self.flags |= dns.opcode.to_flags(dns.opcode.UPDATE) if isinstance(zone, str): zone = dns.name.from_text(zone) self.origin = zone rdclass = dns.rdataclass.RdataClass.make(rdclass) self.zone_rdclass = rdclass if self.origin: self.find_rrset( self.zone, self.origin, rdclass, dns.rdatatype.SOA, create=True, force_unique=True, ) if keyring is not None: self.use_tsig(keyring, keyname, algorithm=keyalgorithm) @property def zone(self) -> List[dns.rrset.RRset]: """The zone section.""" return self.sections[0] @zone.setter def zone(self, v): self.sections[0] = v @property def prerequisite(self) -> List[dns.rrset.RRset]: """The prerequisite section.""" return self.sections[1] @prerequisite.setter def prerequisite(self, v): self.sections[1] = v @property def update(self) -> List[dns.rrset.RRset]: """The update section.""" return self.sections[2] @update.setter def update(self, v): self.sections[2] = v 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.update 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. *replace* is the replacement 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): name = dns.name.from_text(name, None) if isinstance(args[0], dns.rdataset.Rdataset): for rds in args: if replace: self.delete(name, rds.rdtype) for rd in rds: self._add_rr(name, rds.ttl, rd, section=section) else: args = list(args) ttl = int(args.pop(0)) if isinstance(args[0], dns.rdata.Rdata): if replace: self.delete(name, args[0].rdtype) for rd in args: self._add_rr(name, ttl, rd, section=section) else: rdtype = dns.rdatatype.RdataType.make(args.pop(0)) if replace: self.delete(name, rdtype) for s in args: rd = dns.rdata.from_text(self.zone_rdclass, rdtype, s, self.origin) self._add_rr(name, ttl, rd, section=section)
[docs] def add(self, name: Union[dns.name.Name, str], *args: Any) -> None: """Add records. The first argument is always a name. The other arguments can be: - rdataset... - ttl, rdata... - ttl, rdtype, string... """ self._add(False, self.update, name, *args)
[docs] def delete(self, name: Union[dns.name.Name, str], *args: Any) -> None: """Delete records. The first argument is always a name. The other arguments can be: - *empty* - rdataset... - rdata... - rdtype, [string...] """ if isinstance(name, str): name = dns.name.from_text(name, None) if len(args) == 0: self.find_rrset( self.update, name, dns.rdataclass.ANY, dns.rdatatype.ANY, dns.rdatatype.NONE, dns.rdataclass.ANY, True, True, ) elif isinstance(args[0], dns.rdataset.Rdataset): for rds in args: for rd in rds: self._add_rr(name, 0, rd, dns.rdataclass.NONE) else: largs = list(args) if isinstance(largs[0], dns.rdata.Rdata): for rd in largs: self._add_rr(name, 0, rd, dns.rdataclass.NONE) else: rdtype = dns.rdatatype.RdataType.make(largs.pop(0)) if len(largs) == 0: self.find_rrset( self.update, name, self.zone_rdclass, rdtype, dns.rdatatype.NONE, dns.rdataclass.ANY, True, True, ) else: for s in largs: rd = dns.rdata.from_text( self.zone_rdclass, rdtype, s, # type: ignore[arg-type] self.origin, ) self._add_rr(name, 0, rd, dns.rdataclass.NONE)
[docs] def replace(self, name: Union[dns.name.Name, str], *args: Any) -> None: """Replace records. The first argument is always a name. The other arguments can be: - rdataset... - ttl, rdata... - ttl, rdtype, string... Note that if you want to replace the entire node, you should do a delete of the name followed by one or more calls to add. """ self._add(True, self.update, name, *args)
[docs] def present(self, name: Union[dns.name.Name, str], *args: Any) -> None: """Require that an owner name (and optionally an rdata type, or specific rdataset) exists as a prerequisite to the execution of the update. The first argument is always a name. The other arguments can be: - rdataset... - rdata... - rdtype, string... """ if isinstance(name, str): name = dns.name.from_text(name, None) if len(args) == 0: self.find_rrset( self.prerequisite, name, dns.rdataclass.ANY, dns.rdatatype.ANY, dns.rdatatype.NONE, None, True, True, ) elif ( isinstance(args[0], dns.rdataset.Rdataset) or isinstance(args[0], dns.rdata.Rdata) or len(args) > 1 ): if not isinstance(args[0], dns.rdataset.Rdataset): # Add a 0 TTL largs = list(args) largs.insert(0, 0) # type: ignore[arg-type] self._add(False, self.prerequisite, name, *largs) else: self._add(False, self.prerequisite, name, *args) else: rdtype = dns.rdatatype.RdataType.make(args[0]) self.find_rrset( self.prerequisite, name, dns.rdataclass.ANY, rdtype, dns.rdatatype.NONE, None, True, True, )
[docs] def absent( self, name: Union[dns.name.Name, str], rdtype: Optional[Union[dns.rdatatype.RdataType, str]] = None, ) -> None: """Require that an owner name (and optionally an rdata type) does not exist as a prerequisite to the execution of the update.""" if isinstance(name, str): name = dns.name.from_text(name, None) if rdtype is None: self.find_rrset( self.prerequisite, name, dns.rdataclass.NONE, dns.rdatatype.ANY, dns.rdatatype.NONE, None, True, True, ) else: rdtype = dns.rdatatype.RdataType.make(rdtype) self.find_rrset( self.prerequisite, name, dns.rdataclass.NONE, rdtype, dns.rdatatype.NONE, None, True, True, )
def _get_one_rr_per_rrset(self, value): # Updates are always one_rr_per_rrset return True def _parse_rr_header(self, section, name, rdclass, rdtype): deleting = None empty = False if section == UpdateSection.ZONE: if ( dns.rdataclass.is_metaclass(rdclass) or rdtype != dns.rdatatype.SOA or self.zone ): raise dns.exception.FormError else: if not self.zone: raise dns.exception.FormError if rdclass in (dns.rdataclass.ANY, dns.rdataclass.NONE): deleting = rdclass rdclass = self.zone[0].rdclass empty = ( deleting == dns.rdataclass.ANY or section == UpdateSection.PREREQ ) return (rdclass, rdtype, deleting, empty)
# backwards compatibility Update = UpdateMessage ### BEGIN generated UpdateSection constants ZONE = UpdateSection.ZONE PREREQ = UpdateSection.PREREQ UPDATE = UpdateSection.UPDATE ADDITIONAL = UpdateSection.ADDITIONAL ### END generated UpdateSection constants