Update dnspython-2.2.0

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JonnyWong16 2021-10-14 21:36:41 -07:00
parent 4b28040d59
commit 4d62245cf5
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111 changed files with 9077 additions and 5877 deletions

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@ -1,4 +1,6 @@
# Copyright (C) 2001-2007, 2009-2011 Nominum, Inc.
# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2001-2017 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
@ -15,15 +17,14 @@
"""Help for building DNS wire format messages"""
from io import BytesIO
import contextlib
import io
import struct
import random
import time
import sys
import dns.exception
import dns.tsig
from ._compat import long
QUESTION = 0
@ -32,8 +33,7 @@ AUTHORITY = 2
ADDITIONAL = 3
class Renderer(object):
class Renderer:
"""Helper class for building DNS wire-format messages.
Most applications can use the higher-level L{dns.message.Message}
@ -55,43 +55,29 @@ class Renderer(object):
r.add_tsig(keyname, secret, 300, 1, 0, '', request_mac)
wire = r.get_wire()
@ivar output: where rendering is written
@type output: BytesIO object
@ivar id: the message id
@type id: int
@ivar flags: the message flags
@type flags: int
@ivar max_size: the maximum size of the message
@type max_size: int
@ivar origin: the origin to use when rendering relative names
@type origin: dns.name.Name object
@ivar compress: the compression table
@type compress: dict
@ivar section: the section currently being rendered
@type section: int (dns.renderer.QUESTION, dns.renderer.ANSWER,
dns.renderer.AUTHORITY, or dns.renderer.ADDITIONAL)
@ivar counts: list of the number of RRs in each section
@type counts: int list of length 4
@ivar mac: the MAC of the rendered message (if TSIG was used)
@type mac: string
output, an io.BytesIO, where rendering is written
id: the message id
flags: the message flags
max_size: the maximum size of the message
origin: the origin to use when rendering relative names
compress: the compression table
section: an int, the section currently being rendered
counts: list of the number of RRs in each section
mac: the MAC of the rendered message (if TSIG was used)
"""
def __init__(self, id=None, flags=0, max_size=65535, origin=None):
"""Initialize a new renderer.
"""Initialize a new renderer."""
@param id: the message id
@type id: int
@param flags: the DNS message flags
@type flags: int
@param max_size: the maximum message size; the default is 65535.
If rendering results in a message greater than I{max_size},
then L{dns.exception.TooBig} will be raised.
@type max_size: int
@param origin: the origin to use when rendering relative names
@type origin: dns.name.Name or None.
"""
self.output = BytesIO()
self.output = io.BytesIO()
if id is None:
self.id = random.randint(0, 65535)
else:
@ -106,12 +92,9 @@ class Renderer(object):
self.mac = ''
def _rollback(self, where):
"""Truncate the output buffer at offset I{where}, and remove any
"""Truncate the output buffer at offset *where*, and remove any
compression table entries that pointed beyond the truncation
point.
@param where: the offset
@type where: int
"""
self.output.seek(where)
@ -129,9 +112,7 @@ class Renderer(object):
Sections must be rendered order: QUESTION, ANSWER, AUTHORITY,
ADDITIONAL. Sections may be empty.
@param section: the section
@type section: int
@raises dns.exception.FormError: an attempt was made to set
Raises dns.exception.FormError if an attempt was made to set
a section value less than the current section.
"""
@ -140,25 +121,21 @@ class Renderer(object):
raise dns.exception.FormError
self.section = section
def add_question(self, qname, rdtype, rdclass=dns.rdataclass.IN):
"""Add a question to the message.
@contextlib.contextmanager
def _track_size(self):
start = self.output.tell()
yield start
if self.output.tell() > self.max_size:
self._rollback(start)
raise dns.exception.TooBig
@param qname: the question name
@type qname: dns.name.Name
@param rdtype: the question rdata type
@type rdtype: int
@param rdclass: the question rdata class
@type rdclass: int
"""
def add_question(self, qname, rdtype, rdclass=dns.rdataclass.IN):
"""Add a question to the message."""
self._set_section(QUESTION)
before = self.output.tell()
qname.to_wire(self.output, self.compress, self.origin)
self.output.write(struct.pack("!HH", rdtype, rdclass))
after = self.output.tell()
if after >= self.max_size:
self._rollback(before)
raise dns.exception.TooBig
with self._track_size():
qname.to_wire(self.output, self.compress, self.origin)
self.output.write(struct.pack("!HH", rdtype, rdclass))
self.counts[QUESTION] += 1
def add_rrset(self, section, rrset, **kw):
@ -166,20 +143,11 @@ class Renderer(object):
Any keyword arguments are passed on to the rdataset's to_wire()
routine.
@param section: the section
@type section: int
@param rrset: the rrset
@type rrset: dns.rrset.RRset object
"""
self._set_section(section)
before = self.output.tell()
n = rrset.to_wire(self.output, self.compress, self.origin, **kw)
after = self.output.tell()
if after >= self.max_size:
self._rollback(before)
raise dns.exception.TooBig
with self._track_size():
n = rrset.to_wire(self.output, self.compress, self.origin, **kw)
self.counts[section] += n
def add_rdataset(self, section, name, rdataset, **kw):
@ -188,124 +156,79 @@ class Renderer(object):
Any keyword arguments are passed on to the rdataset's to_wire()
routine.
@param section: the section
@type section: int
@param name: the owner name
@type name: dns.name.Name object
@param rdataset: the rdataset
@type rdataset: dns.rdataset.Rdataset object
"""
self._set_section(section)
before = self.output.tell()
n = rdataset.to_wire(name, self.output, self.compress, self.origin,
**kw)
after = self.output.tell()
if after >= self.max_size:
self._rollback(before)
raise dns.exception.TooBig
with self._track_size():
n = rdataset.to_wire(name, self.output, self.compress, self.origin,
**kw)
self.counts[section] += n
def add_edns(self, edns, ednsflags, payload, options=None):
"""Add an EDNS OPT record to the message.
@param edns: The EDNS level to use.
@type edns: int
@param ednsflags: EDNS flag values.
@type ednsflags: int
@param payload: The EDNS sender's payload field, which is the maximum
size of UDP datagram the sender can handle.
@type payload: int
@param options: The EDNS options list
@type options: list of dns.edns.Option instances
@see: RFC 2671
"""
"""Add an EDNS OPT record to the message."""
# make sure the EDNS version in ednsflags agrees with edns
ednsflags &= long(0xFF00FFFF)
ednsflags &= 0xFF00FFFF
ednsflags |= (edns << 16)
self._set_section(ADDITIONAL)
before = self.output.tell()
self.output.write(struct.pack('!BHHIH', 0, dns.rdatatype.OPT, payload,
ednsflags, 0))
if options is not None:
lstart = self.output.tell()
for opt in options:
stuff = struct.pack("!HH", opt.otype, 0)
self.output.write(stuff)
start = self.output.tell()
opt.to_wire(self.output)
end = self.output.tell()
assert end - start < 65536
self.output.seek(start - 2)
stuff = struct.pack("!H", end - start)
self.output.write(stuff)
self.output.seek(0, 2)
lend = self.output.tell()
assert lend - lstart < 65536
self.output.seek(lstart - 2)
stuff = struct.pack("!H", lend - lstart)
self.output.write(stuff)
self.output.seek(0, 2)
after = self.output.tell()
if after >= self.max_size:
self._rollback(before)
raise dns.exception.TooBig
self.counts[ADDITIONAL] += 1
opt = dns.message.Message._make_opt(ednsflags, payload, options)
self.add_rrset(ADDITIONAL, opt)
def add_tsig(self, keyname, secret, fudge, id, tsig_error, other_data,
request_mac, algorithm=dns.tsig.default_algorithm):
"""Add a TSIG signature to the message.
"""Add a TSIG signature to the message."""
@param keyname: the TSIG key name
@type keyname: dns.name.Name object
@param secret: the secret to use
@type secret: string
@param fudge: TSIG time fudge
@type fudge: int
@param id: the message id to encode in the tsig signature
@type id: int
@param tsig_error: TSIG error code; default is 0.
@type tsig_error: int
@param other_data: TSIG other data.
@type other_data: string
@param request_mac: This message is a response to the request which
had the specified MAC.
@type request_mac: string
@param algorithm: the TSIG algorithm to use
@type algorithm: dns.name.Name object
"""
self._set_section(ADDITIONAL)
before = self.output.tell()
s = self.output.getvalue()
(tsig_rdata, self.mac, ctx) = dns.tsig.sign(s,
keyname,
secret,
int(time.time()),
fudge,
id,
tsig_error,
other_data,
request_mac,
algorithm=algorithm)
keyname.to_wire(self.output, self.compress, self.origin)
self.output.write(struct.pack('!HHIH', dns.rdatatype.TSIG,
dns.rdataclass.ANY, 0, 0))
rdata_start = self.output.tell()
self.output.write(tsig_rdata)
if isinstance(secret, dns.tsig.Key):
key = secret
else:
key = dns.tsig.Key(keyname, secret, algorithm)
tsig = dns.message.Message._make_tsig(keyname, algorithm, 0, fudge,
b'', id, tsig_error, other_data)
(tsig, _) = dns.tsig.sign(s, key, tsig[0], int(time.time()),
request_mac)
self._write_tsig(tsig, keyname)
def add_multi_tsig(self, ctx, keyname, secret, fudge, id, tsig_error,
other_data, request_mac,
algorithm=dns.tsig.default_algorithm):
"""Add a TSIG signature to the message. Unlike add_tsig(), this can be
used for a series of consecutive DNS envelopes, e.g. for a zone
transfer over TCP [RFC2845, 4.4].
For the first message in the sequence, give ctx=None. For each
subsequent message, give the ctx that was returned from the
add_multi_tsig() call for the previous message."""
s = self.output.getvalue()
if isinstance(secret, dns.tsig.Key):
key = secret
else:
key = dns.tsig.Key(keyname, secret, algorithm)
tsig = dns.message.Message._make_tsig(keyname, algorithm, 0, fudge,
b'', id, tsig_error, other_data)
(tsig, ctx) = dns.tsig.sign(s, key, tsig[0], int(time.time()),
request_mac, ctx, True)
self._write_tsig(tsig, keyname)
return ctx
def _write_tsig(self, tsig, keyname):
self._set_section(ADDITIONAL)
with self._track_size():
keyname.to_wire(self.output, self.compress, self.origin)
self.output.write(struct.pack('!HHIH', dns.rdatatype.TSIG,
dns.rdataclass.ANY, 0, 0))
rdata_start = self.output.tell()
tsig.to_wire(self.output)
after = self.output.tell()
assert after - rdata_start < 65536
if after >= self.max_size:
self._rollback(before)
raise dns.exception.TooBig
self.output.seek(rdata_start - 2)
self.output.write(struct.pack('!H', after - rdata_start))
self.counts[ADDITIONAL] += 1
self.output.seek(10)
self.output.write(struct.pack('!H', self.counts[ADDITIONAL]))
self.output.seek(0, 2)
self.output.seek(0, io.SEEK_END)
def write_header(self):
"""Write the DNS message header.
@ -319,12 +242,9 @@ class Renderer(object):
self.output.write(struct.pack('!HHHHHH', self.id, self.flags,
self.counts[0], self.counts[1],
self.counts[2], self.counts[3]))
self.output.seek(0, 2)
self.output.seek(0, io.SEEK_END)
def get_wire(self):
"""Return the wire format message.
@rtype: string
"""
"""Return the wire format message."""
return self.output.getvalue()