1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
# 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"""
import dns.message
import dns.name
import dns.opcode
import dns.rdata
import dns.rdataclass
import dns.rdataset
import dns.tsig
class Update(dns.message.Message):
def __init__(self, zone, rdclass=dns.rdataclass.IN, keyring=None,
keyname=None, keyalgorithm=dns.tsig.default_algorithm):
"""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`` or ``str``, the zone which is being
updated.
*rdclass*, an ``int`` or ``str``, the class of the zone.
*keyring*, a ``dict``, the TSIG keyring to use. If a
*keyring* is specified but a *keyname* is not, then the key
used will be the first key in the *keyring*. Note that the
order of keys in a dictionary is not defined, so applications
should supply a keyname when a keyring is used, unless they
know the keyring contains only one key.
*keyname*, a ``dns.name.Name`` or ``None``, the name of the TSIG key
to use; defaults to ``None``. The key must be defined in the keyring.
*keyalgorithm*, a ``dns.name.Name``, the TSIG algorithm to use.
"""
super(Update, self).__init__()
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
self.find_rrset(self.question, self.origin, rdclass, dns.rdatatype.SOA,
create=True, force_unique=True)
if keyring is not None:
self.use_tsig(keyring, keyname, algorithm=keyalgorithm)
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.authority
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, *args):
"""Add records.
The first argument is always a name. The other
arguments can be:
- rdataset...
- ttl, rdata...
- ttl, rdtype, string...
"""
self._add(False, self.authority, name, *args)
def delete(self, name, *args):
"""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.authority, name, dns.rdataclass.ANY,
dns.rdatatype.ANY, dns.rdatatype.NONE,
dns.rdatatype.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:
args = list(args)
if isinstance(args[0], dns.rdata.Rdata):
for rd in args:
self._add_rr(name, 0, rd, dns.rdataclass.NONE)
else:
rdtype = dns.rdatatype.RdataType.make(args.pop(0))
if len(args) == 0:
self.find_rrset(self.authority, name,
self.zone_rdclass, rdtype,
dns.rdatatype.NONE,
dns.rdataclass.ANY,
True, True)
else:
for s in args:
rd = dns.rdata.from_text(self.zone_rdclass, rdtype, s,
self.origin)
self._add_rr(name, 0, rd, dns.rdataclass.NONE)
def replace(self, name, *args):
"""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.authority, name, *args)
def present(self, name, *args):
"""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.answer, 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
args = list(args)
args.insert(0, 0)
self._add(False, self.answer, name, *args)
else:
rdtype = dns.rdatatype.RdataType.make(args[0])
self.find_rrset(self.answer, name,
dns.rdataclass.ANY, rdtype,
dns.rdatatype.NONE, None,
True, True)
def absent(self, name, rdtype=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.answer, name,
dns.rdataclass.NONE, dns.rdatatype.ANY,
dns.rdatatype.NONE, None,
True, True)
else:
rdtype = dns.rdatatype.RdataType.make(rdtype)
self.find_rrset(self.answer, name,
dns.rdataclass.NONE, rdtype,
dns.rdatatype.NONE, None,
True, True)
def to_wire(self, origin=None, max_size=65535):
"""Return a string containing the update in DNS compressed wire
format.
*origin*, a ``dns.name.Name`` or ``None``, the origin to be
appended to any relative names. If *origin* is ``None``, then
the origin of the ``dns.update.Update`` message object is used
(i.e. the *zone* parameter passed when the Update object was
created).
*max_size*, an ``int``, the maximum size of the wire format
output; default is 0, which means "the message's request
payload, if nonzero, or 65535".
Returns a ``bytes``.
"""
if origin is None:
origin = self.origin
return super(Update, self).to_wire(origin, max_size)
|
