binder/binder/models.py

158 lines
6.2 KiB
Python

### Binder Models
# Standard Imports
import binascii
import socket
import urllib2
# 3rd Party
from pybindxml import reader as bindreader
import dns.exception
import dns.query
import dns.tsig
import dns.zone
# App Imports
from binder import exceptions
from django.db import models
TSIG_ALGORITHMS = (('HMAC-MD5.SIG-ALG.REG.INT', 'MD5'),
('hmac-sha1', 'SHA1'),
('hmac-sha256', 'SHA256'),
('hmac-sha384', 'SHA384'),
('hmac-sha512', 'SHA512'))
class Key(models.Model):
""" Store and reference TSIG keys.
TODO: Should/Can we encrypt these DNS keys in the DB?
"""
name = models.CharField(max_length=255,
unique=True,
help_text="A human readable name for the key to store, used for "
"further references to the key.")
data = models.CharField(max_length=255,
help_text="The private part of the TSIG key.")
algorithm = models.CharField(max_length=255,
choices=TSIG_ALGORITHMS,
help_text="The algorithm which has been used for the key.")
def __unicode__(self):
return self.name
class Meta:
ordering = ["name"]
def create_keyring(self):
if self.name is None:
return None
try:
keyring = dns.tsigkeyring.from_text({self.name: self.data})
except binascii.Error, err:
raise exceptions.KeyringException("Incorrect key data. Verify key: %s. Reason: %s" % (self.name, err))
return keyring
class BindServer(models.Model):
""" Store DNS servers and attributes for referencing their
statistics ports. Also reference FK for TSIG transfer keys,
if required.
"""
hostname = models.CharField(max_length=255,
unique=True,
help_text="Host name or IP address of the BIND server.")
dns_port = models.IntegerField(default=53,
verbose_name="DNS port",
help_text="The port where the BIND server is listening for DNS "
"requests. binder especially uses that port for the dynamic "
"zone updates. In most cases you should always leave it at the "
"default port 53.")
statistics_port = models.IntegerField(help_text="Port where the BIND server is serving "
"statistics on.")
default_transfer_key = models.ForeignKey(Key,
null=True,
blank=True,
help_text="The default key to use for all actions "
"with this DNS server as long as no other key is "
"specified explicitly.")
def __unicode__(self):
return self.hostname
class Meta:
ordering = ["hostname"]
def list_zones(self):
""" List the DNS zones and attributes.
TODO: Parse these XML more intelligently. Grab the view name. Any other data available?
Returns:
List of Dicts { String view_name,
String zone_name,
String zone_class,
String zone_serial }
"""
zone_data = bindreader.BindXmlReader(host=self.hostname, port=self.statistics_port)
zone_data.get_stats()
return zone_data
def list_zone_records(self, zone_name):
""" List all records in a specific zone.
TODO: Print out current_record in the loop and see if we can parse this more programatically,
rather than just splitting on space. What is the difference between class and type?
Arguments:
String zone_name: Name of the zone
Returns:
List of Dicts { String rr_name, String rr_ttl, String rr_class, String rr_type, String rr_data }
"""
try:
transfer_key = Key.objects.get(name=self.default_transfer_key)
except Key.DoesNotExist:
keyring = None
algorithm = None
else:
keyring = transfer_key.create_keyring()
algorithm = transfer_key.algorithm
try:
zone = dns.zone.from_xfr(dns.query.xfr(self.hostname,
zone_name,
port=self.dns_port,
keyring=keyring,
keyalgorithm=algorithm))
except dns.tsig.PeerBadKey:
# The incorrect TSIG key was selected for transfers.
raise exceptions.TransferException("Unable to list zone records because of a TSIG key mismatch.")
except socket.error, err:
# Thrown when the DNS server does not respond for a zone transfer (XFR).
raise exceptions.TransferException("DNS server did not respond for transfer. Reason: %s" % err)
except dns.exception.FormError:
# When the DNS message is malformed.
# * Can happen if a TSIG key is required but a default_transfer_key is not specified.
raise exceptions.TransferException("Unable to perform AXFR to list zone records. Did you forget to specify a default transfer key?")
names = zone.nodes.keys()
names.sort()
record_array = []
for current_name in names:
current_record = zone[current_name].to_text(current_name)
for split_record in current_record.split("\n"):
current_record = split_record.split(" ")
rr_dict = {}
rr_dict["rr_name"] = current_record[0]
rr_dict["rr_ttl"] = current_record[1]
rr_dict["rr_class"] = current_record[2]
rr_dict["rr_type"] = current_record[3]
rr_dict["rr_data"] = current_record[4]
record_array.append(rr_dict)
return record_array