mirror of https://github.com/morpheus65535/bazarr
314 lines
12 KiB
Python
314 lines
12 KiB
Python
|
# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
|
||
|
|
|
||
|
|
# Copyright (C) 2003-2017 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.
|
||
|
|
|
||
|
|
import dns.exception
|
||
|
|
import dns.message
|
||
|
|
import dns.name
|
||
|
|
import dns.rcode
|
||
|
|
import dns.serial
|
||
|
|
import dns.rdatatype
|
||
|
|
import dns.zone
|
||
|
|
|
||
|
|
|
||
|
|
class TransferError(dns.exception.DNSException):
|
||
|
|
"""A zone transfer response got a non-zero rcode."""
|
||
|
|
|
||
|
|
def __init__(self, rcode):
|
||
|
|
message = 'Zone transfer error: %s' % dns.rcode.to_text(rcode)
|
||
|
|
super().__init__(message)
|
||
|
|
self.rcode = rcode
|
||
|
|
|
||
|
|
|
||
|
|
class SerialWentBackwards(dns.exception.FormError):
|
||
|
|
"""The current serial number is less than the serial we know."""
|
||
|
|
|
||
|
|
|
||
|
|
class UseTCP(dns.exception.DNSException):
|
||
|
|
"""This IXFR cannot be completed with UDP."""
|
||
|
|
|
||
|
|
|
||
|
|
class Inbound:
|
||
|
|
"""
|
||
|
|
State machine for zone transfers.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, txn_manager, rdtype=dns.rdatatype.AXFR,
|
||
|
|
serial=None, is_udp=False):
|
||
|
|
"""Initialize an inbound zone transfer.
|
||
|
|
|
||
|
|
*txn_manager* is a :py:class:`dns.transaction.TransactionManager`.
|
||
|
|
|
||
|
|
*rdtype* can be `dns.rdatatype.AXFR` or `dns.rdatatype.IXFR`
|
||
|
|
|
||
|
|
*serial* is the base serial number for IXFRs, and is required in
|
||
|
|
that case.
|
||
|
|
|
||
|
|
*is_udp*, a ``bool`` indidicates if UDP is being used for this
|
||
|
|
XFR.
|
||
|
|
"""
|
||
|
|
self.txn_manager = txn_manager
|
||
|
|
self.txn = None
|
||
|
|
self.rdtype = rdtype
|
||
|
|
if rdtype == dns.rdatatype.IXFR:
|
||
|
|
if serial is None:
|
||
|
|
raise ValueError('a starting serial must be supplied for IXFRs')
|
||
|
|
elif is_udp:
|
||
|
|
raise ValueError('is_udp specified for AXFR')
|
||
|
|
self.serial = serial
|
||
|
|
self.is_udp = is_udp
|
||
|
|
(_, _, self.origin) = txn_manager.origin_information()
|
||
|
|
self.soa_rdataset = None
|
||
|
|
self.done = False
|
||
|
|
self.expecting_SOA = False
|
||
|
|
self.delete_mode = False
|
||
|
|
|
||
|
|
def process_message(self, message):
|
||
|
|
"""Process one message in the transfer.
|
||
|
|
|
||
|
|
The message should have the same relativization as was specified when
|
||
|
|
the `dns.xfr.Inbound` was created. The message should also have been
|
||
|
|
created with `one_rr_per_rrset=True` because order matters.
|
||
|
|
|
||
|
|
Returns `True` if the transfer is complete, and `False` otherwise.
|
||
|
|
"""
|
||
|
|
if self.txn is None:
|
||
|
|
replacement = self.rdtype == dns.rdatatype.AXFR
|
||
|
|
self.txn = self.txn_manager.writer(replacement)
|
||
|
|
rcode = message.rcode()
|
||
|
|
if rcode != dns.rcode.NOERROR:
|
||
|
|
raise TransferError(rcode)
|
||
|
|
#
|
||
|
|
# We don't require a question section, but if it is present is
|
||
|
|
# should be correct.
|
||
|
|
#
|
||
|
|
if len(message.question) > 0:
|
||
|
|
if message.question[0].name != self.origin:
|
||
|
|
raise dns.exception.FormError("wrong question name")
|
||
|
|
if message.question[0].rdtype != self.rdtype:
|
||
|
|
raise dns.exception.FormError("wrong question rdatatype")
|
||
|
|
answer_index = 0
|
||
|
|
if self.soa_rdataset is None:
|
||
|
|
#
|
||
|
|
# This is the first message. We're expecting an SOA at
|
||
|
|
# the origin.
|
||
|
|
#
|
||
|
|
if not message.answer or message.answer[0].name != self.origin:
|
||
|
|
raise dns.exception.FormError("No answer or RRset not "
|
||
|
|
"for zone origin")
|
||
|
|
rrset = message.answer[0]
|
||
|
|
name = rrset.name
|
||
|
|
rdataset = rrset
|
||
|
|
if rdataset.rdtype != dns.rdatatype.SOA:
|
||
|
|
raise dns.exception.FormError("first RRset is not an SOA")
|
||
|
|
answer_index = 1
|
||
|
|
self.soa_rdataset = rdataset.copy()
|
||
|
|
if self.rdtype == dns.rdatatype.IXFR:
|
||
|
|
if self.soa_rdataset[0].serial == self.serial:
|
||
|
|
#
|
||
|
|
# We're already up-to-date.
|
||
|
|
#
|
||
|
|
self.done = True
|
||
|
|
elif dns.serial.Serial(self.soa_rdataset[0].serial) < \
|
||
|
|
self.serial:
|
||
|
|
# It went backwards!
|
||
|
|
raise SerialWentBackwards
|
||
|
|
else:
|
||
|
|
if self.is_udp and len(message.answer[answer_index:]) == 0:
|
||
|
|
#
|
||
|
|
# There are no more records, so this is the
|
||
|
|
# "truncated" response. Say to use TCP
|
||
|
|
#
|
||
|
|
raise UseTCP
|
||
|
|
#
|
||
|
|
# Note we're expecting another SOA so we can detect
|
||
|
|
# if this IXFR response is an AXFR-style response.
|
||
|
|
#
|
||
|
|
self.expecting_SOA = True
|
||
|
|
#
|
||
|
|
# Process the answer section (other than the initial SOA in
|
||
|
|
# the first message).
|
||
|
|
#
|
||
|
|
for rrset in message.answer[answer_index:]:
|
||
|
|
name = rrset.name
|
||
|
|
rdataset = rrset
|
||
|
|
if self.done:
|
||
|
|
raise dns.exception.FormError("answers after final SOA")
|
||
|
|
if rdataset.rdtype == dns.rdatatype.SOA and \
|
||
|
|
name == self.origin:
|
||
|
|
#
|
||
|
|
# Every time we see an origin SOA delete_mode inverts
|
||
|
|
#
|
||
|
|
if self.rdtype == dns.rdatatype.IXFR:
|
||
|
|
self.delete_mode = not self.delete_mode
|
||
|
|
#
|
||
|
|
# If this SOA Rdataset is equal to the first we saw
|
||
|
|
# then we're finished. If this is an IXFR we also
|
||
|
|
# check that we're seeing the record in the expected
|
||
|
|
# part of the response.
|
||
|
|
#
|
||
|
|
if rdataset == self.soa_rdataset and \
|
||
|
|
(self.rdtype == dns.rdatatype.AXFR or
|
||
|
|
(self.rdtype == dns.rdatatype.IXFR and
|
||
|
|
self.delete_mode)):
|
||
|
|
#
|
||
|
|
# This is the final SOA
|
||
|
|
#
|
||
|
|
if self.expecting_SOA:
|
||
|
|
# We got an empty IXFR sequence!
|
||
|
|
raise dns.exception.FormError('empty IXFR sequence')
|
||
|
|
if self.rdtype == dns.rdatatype.IXFR \
|
||
|
|
and self.serial != rdataset[0].serial:
|
||
|
|
raise dns.exception.FormError('unexpected end of IXFR '
|
||
|
|
'sequence')
|
||
|
|
self.txn.replace(name, rdataset)
|
||
|
|
self.txn.commit()
|
||
|
|
self.txn = None
|
||
|
|
self.done = True
|
||
|
|
else:
|
||
|
|
#
|
||
|
|
# This is not the final SOA
|
||
|
|
#
|
||
|
|
self.expecting_SOA = False
|
||
|
|
if self.rdtype == dns.rdatatype.IXFR:
|
||
|
|
if self.delete_mode:
|
||
|
|
# This is the start of an IXFR deletion set
|
||
|
|
if rdataset[0].serial != self.serial:
|
||
|
|
raise dns.exception.FormError(
|
||
|
|
"IXFR base serial mismatch")
|
||
|
|
else:
|
||
|
|
# This is the start of an IXFR addition set
|
||
|
|
self.serial = rdataset[0].serial
|
||
|
|
self.txn.replace(name, rdataset)
|
||
|
|
else:
|
||
|
|
# We saw a non-final SOA for the origin in an AXFR.
|
||
|
|
raise dns.exception.FormError('unexpected origin SOA '
|
||
|
|
'in AXFR')
|
||
|
|
continue
|
||
|
|
if self.expecting_SOA:
|
||
|
|
#
|
||
|
|
# We made an IXFR request and are expecting another
|
||
|
|
# SOA RR, but saw something else, so this must be an
|
||
|
|
# AXFR response.
|
||
|
|
#
|
||
|
|
self.rdtype = dns.rdatatype.AXFR
|
||
|
|
self.expecting_SOA = False
|
||
|
|
self.delete_mode = False
|
||
|
|
self.txn.rollback()
|
||
|
|
self.txn = self.txn_manager.writer(True)
|
||
|
|
#
|
||
|
|
# Note we are falling through into the code below
|
||
|
|
# so whatever rdataset this was gets written.
|
||
|
|
#
|
||
|
|
# Add or remove the data
|
||
|
|
if self.delete_mode:
|
||
|
|
self.txn.delete_exact(name, rdataset)
|
||
|
|
else:
|
||
|
|
self.txn.add(name, rdataset)
|
||
|
|
if self.is_udp and not self.done:
|
||
|
|
#
|
||
|
|
# This is a UDP IXFR and we didn't get to done, and we didn't
|
||
|
|
# get the proper "truncated" response
|
||
|
|
#
|
||
|
|
raise dns.exception.FormError('unexpected end of UDP IXFR')
|
||
|
|
return self.done
|
||
|
|
|
||
|
|
#
|
||
|
|
# Inbounds are context managers.
|
||
|
|
#
|
||
|
|
|
||
|
|
def __enter__(self):
|
||
|
|
return self
|
||
|
|
|
||
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
||
|
|
if self.txn:
|
||
|
|
self.txn.rollback()
|
||
|
|
return False
|
||
|
|
|
||
|
|
|
||
|
|
def make_query(txn_manager, serial=0,
|
||
|
|
use_edns=None, ednsflags=None, payload=None,
|
||
|
|
request_payload=None, options=None,
|
||
|
|
keyring=None, keyname=None,
|
||
|
|
keyalgorithm=dns.tsig.default_algorithm):
|
||
|
|
"""Make an AXFR or IXFR query.
|
||
|
|
|
||
|
|
*txn_manager* is a ``dns.transaction.TransactionManager``, typically a
|
||
|
|
``dns.zone.Zone``.
|
||
|
|
|
||
|
|
*serial* is an ``int`` or ``None``. If 0, then IXFR will be
|
||
|
|
attempted using the most recent serial number from the
|
||
|
|
*txn_manager*; it is the caller's responsibility to ensure there
|
||
|
|
are no write transactions active that could invalidate the
|
||
|
|
retrieved serial. If a serial cannot be determined, AXFR will be
|
||
|
|
forced. Other integer values are the starting serial to use.
|
||
|
|
``None`` forces an AXFR.
|
||
|
|
|
||
|
|
Please see the documentation for :py:func:`dns.message.make_query` and
|
||
|
|
:py:func:`dns.message.Message.use_tsig` for details on the other parameters
|
||
|
|
to this function.
|
||
|
|
|
||
|
|
Returns a `(query, serial)` tuple.
|
||
|
|
"""
|
||
|
|
(zone_origin, _, origin) = txn_manager.origin_information()
|
||
|
|
if serial is None:
|
||
|
|
rdtype = dns.rdatatype.AXFR
|
||
|
|
elif not isinstance(serial, int):
|
||
|
|
raise ValueError('serial is not an integer')
|
||
|
|
elif serial == 0:
|
||
|
|
with txn_manager.reader() as txn:
|
||
|
|
rdataset = txn.get(origin, 'SOA')
|
||
|
|
if rdataset:
|
||
|
|
serial = rdataset[0].serial
|
||
|
|
rdtype = dns.rdatatype.IXFR
|
||
|
|
else:
|
||
|
|
serial = None
|
||
|
|
rdtype = dns.rdatatype.AXFR
|
||
|
|
elif serial > 0 and serial < 4294967296:
|
||
|
|
rdtype = dns.rdatatype.IXFR
|
||
|
|
else:
|
||
|
|
raise ValueError('serial out-of-range')
|
||
|
|
rdclass = txn_manager.get_class()
|
||
|
|
q = dns.message.make_query(zone_origin, rdtype, rdclass,
|
||
|
|
use_edns, False, ednsflags, payload,
|
||
|
|
request_payload, options)
|
||
|
|
if serial is not None:
|
||
|
|
rdata = dns.rdata.from_text(rdclass, 'SOA', f'. . {serial} 0 0 0 0')
|
||
|
|
rrset = q.find_rrset(q.authority, zone_origin, rdclass,
|
||
|
|
dns.rdatatype.SOA, create=True)
|
||
|
|
rrset.add(rdata, 0)
|
||
|
|
if keyring is not None:
|
||
|
|
q.use_tsig(keyring, keyname, algorithm=keyalgorithm)
|
||
|
|
return (q, serial)
|
||
|
|
|
||
|
|
def extract_serial_from_query(query):
|
||
|
|
"""Extract the SOA serial number from query if it is an IXFR and return
|
||
|
|
it, otherwise return None.
|
||
|
|
|
||
|
|
*query* is a dns.message.QueryMessage that is an IXFR or AXFR request.
|
||
|
|
|
||
|
|
Raises if the query is not an IXFR or AXFR, or if an IXFR doesn't have
|
||
|
|
an appropriate SOA RRset in the authority section."""
|
||
|
|
|
||
|
|
question = query.question[0]
|
||
|
|
if question.rdtype == dns.rdatatype.AXFR:
|
||
|
|
return None
|
||
|
|
elif question.rdtype != dns.rdatatype.IXFR:
|
||
|
|
raise ValueError("query is not an AXFR or IXFR")
|
||
|
|
soa = query.find_rrset(query.authority, question.name, question.rdclass,
|
||
|
|
dns.rdatatype.SOA)
|
||
|
|
return soa[0].serial
|