# 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
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)
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)
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)
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)
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,
)
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
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