Source code for dns.update

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

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"""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.rdatatype
import dns.rdataset
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: the_rdtype = dns.rdatatype.RdataType.make(rdtype) self.find_rrset( self.prerequisite, name, dns.rdataclass.NONE, the_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