binder/binder/models.py

145 lines
5.1 KiB
Python

### Binder Models
# Standard Imports
import socket
import urllib2
# 3rd Party
from BeautifulSoup import BeautifulStoneSoup as BS
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', '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)
data = models.CharField(max_length=255)
algorithm = models.CharField(max_length=255, choices=TSIG_ALGORITHMS)
def __unicode__(self):
return self.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" % (key_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)
statistics_port = models.IntegerField()
default_transfer_key = models.ForeignKey(Key, null=True, blank=True)
def __unicode__(self):
return self.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_req = urllib2.Request("http://%s:%s" % (self.hostname, self.statistics_port))
try:
http_request = urllib2.urlopen(zone_req)
except urllib2.URLError, err:
raise exceptions.ZoneException(err)
return_array = []
xmloutput = http_request.read()
mysoup = BS(xmloutput)
views = mysoup.findAll("view")
for view in views:
view_name = view.find("name").string
for zone in view.findAll("zone"):
zone_name, zone_class = zone.find("name").string.split("/")
zone_serial = zone.find("serial").string
if zone_class == "IN":
return_array.append({"view_name" : view_name,
"zone_name" : zone_name,
"zone_class" : zone_class,
"zone_serial" : zone_serial })
return return_array
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)
keyring = transfer_key.create_keyring()
except Key.DoesNotExist:
keyring = None
try:
zone = dns.zone.from_xfr(dns.query.xfr(self.hostname, zone_name, keyring=keyring))
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