netbox-ddns/netbox_ddns/models.py
2020-04-19 22:19:12 +02:00

366 lines
11 KiB
Python

import logging
import socket
from typing import Optional
import dns.tsigkeyring
import dns.update
from django.core.exceptions import ValidationError
from django.db import models
from django.db.models.functions import Length
from django.utils.html import format_html
from django.utils.translation import gettext_lazy as _
from dns import rcode
from dns.tsig import HMAC_MD5, HMAC_SHA1, HMAC_SHA224, HMAC_SHA256, HMAC_SHA384, HMAC_SHA512
from netaddr import ip
from ipam.fields import IPNetworkField
from ipam.models import IPAddress
from .utils import normalize_fqdn
from .validators import HostnameAddressValidator, HostnameValidator, validate_base64
logger = logging.getLogger('netbox_ddns')
TSIG_ALGORITHM_CHOICES = (
(str(HMAC_MD5), 'HMAC MD5'),
(str(HMAC_SHA1), 'HMAC SHA1'),
(str(HMAC_SHA224), 'HMAC SHA224'),
(str(HMAC_SHA256), 'HMAC SHA256'),
(str(HMAC_SHA384), 'HMAC SHA384'),
(str(HMAC_SHA512), 'HMAC SHA512'),
)
ACTION_CREATE = 1
ACTION_DELETE = 2
ACTION_CHOICES = (
(ACTION_CREATE, 'Create'),
(ACTION_DELETE, 'Delete'),
)
def get_rcode_display(code):
if code is None:
return None
elif code == rcode.NOERROR:
return _('Success')
elif code == rcode.SERVFAIL:
return _('Server failure')
elif code == rcode.NXDOMAIN:
return _('Name does not exist')
elif code == rcode.NOTIMP:
return _('Not implemented')
elif code == rcode.REFUSED:
return _('Refused')
elif code == rcode.NOTAUTH:
return _('Server not authoritative')
else:
return _('Unknown response: {}').format(code)
class Server(models.Model):
server = models.CharField(
verbose_name=_('DDNS Server'),
max_length=255,
validators=[HostnameAddressValidator()],
)
tsig_key_name = models.CharField(
verbose_name=_('TSIG Key Name'),
max_length=255,
validators=[HostnameValidator()],
)
tsig_algorithm = models.CharField(
verbose_name=_('TSIG Algorithm'),
max_length=32, # Longest is 24 chars for historic reasons, new ones are shorter, so 32 is more than enough
choices=TSIG_ALGORITHM_CHOICES,
)
tsig_key = models.CharField(
verbose_name=_('TSIG Key'),
max_length=512,
validators=[validate_base64],
help_text=_('in base64 notation'),
)
class Meta:
unique_together = (
('server', 'tsig_key_name'),
)
ordering = ('server', 'tsig_key_name')
verbose_name = _('dynamic DNS Server')
verbose_name_plural = _('dynamic DNS Servers')
def __str__(self):
return f'{self.server} ({self.tsig_key_name})'
def clean(self):
# Remove trailing dots from the server name/address
self.server = self.server.lower().rstrip('.')
# Ensure trailing dots from domain-style fields
self.tsig_key_name = normalize_fqdn(self.tsig_key_name.lower().rstrip('.'))
@property
def address(self) -> Optional[str]:
addrinfo = socket.getaddrinfo(self.server, 'domain', proto=socket.IPPROTO_UDP)
for family, _, _, _, sockaddr in addrinfo:
if family in (socket.AF_INET, socket.AF_INET6) and sockaddr[0]:
return sockaddr[0]
def create_update(self, zone: str) -> dns.update.Update:
return dns.update.Update(
zone=normalize_fqdn(zone),
keyring=dns.tsigkeyring.from_text({
self.tsig_key_name: self.tsig_key
}),
keyname=self.tsig_key_name,
keyalgorithm=self.tsig_algorithm
)
class ZoneQuerySet(models.QuerySet):
def find_for_dns_name(self, dns_name: str) -> Optional['Zone']:
# Generate all possible zones
zones = []
parts = dns_name.lower().split('.')
for i in range(len(parts)):
zones.append('.'.join(parts[-i - 1:]))
# Find the zone, if any
return self.filter(name__in=zones).order_by(Length('name').desc()).first()
class Zone(models.Model):
name = models.CharField(
verbose_name=_('zone name'),
max_length=255,
validators=[HostnameValidator()],
unique=True,
)
ttl = models.PositiveIntegerField(
verbose_name=_('TTL'),
)
server = models.ForeignKey(
to=Server,
verbose_name=_('DDNS Server'),
on_delete=models.PROTECT,
)
objects = ZoneQuerySet.as_manager()
class Meta:
ordering = ('name',)
verbose_name = _('forward zone')
verbose_name_plural = _('forward zones')
def __str__(self):
return self.name
def clean(self):
# Ensure trailing dots from domain-style fields
self.name = normalize_fqdn(self.name)
def get_updater(self):
return self.server.create_update(self.name)
class ReverseZoneQuerySet(models.QuerySet):
def find_for_address(self, address: ip.IPAddress) -> Optional['ReverseZone']:
# Find the zone, if any
zones = list(ReverseZone.objects.filter(prefix__net_contains=address))
if not zones:
return None
zones.sort(key=lambda zone: zone.prefix.prefixlen)
return zones[-1]
class ReverseZone(models.Model):
prefix = IPNetworkField(
verbose_name=_('prefix'),
unique=True,
)
name = models.CharField(
verbose_name=_('reverse zone name'),
max_length=255,
blank=True,
help_text=_("RFC 2317 style reverse DNS, required when the prefix doesn't map to a reverse zone"),
)
ttl = models.PositiveIntegerField(
verbose_name=_('TTL'),
)
server = models.ForeignKey(
to=Server,
verbose_name=_('DDNS Server'),
on_delete=models.PROTECT,
)
objects = ReverseZoneQuerySet.as_manager()
class Meta:
ordering = ('prefix',)
verbose_name = _('reverse zone')
verbose_name_plural = _('reverse zones')
def __str__(self):
return f'for {self.prefix}'
def record_name(self, address: ip.IPAddress):
record_name = self.name
if self.prefix.version == 4:
for pos, octet in enumerate(address.words):
if (pos + 1) * 8 <= self.prefix.prefixlen:
continue
record_name = f'{octet}.{record_name}'
else:
nibbles = f'{address.value:032x}'
for pos, nibble in enumerate(nibbles):
if (pos + 1) * 4 <= self.prefix.prefixlen:
continue
record_name = f'{nibble}.{record_name}'
return record_name
def clean(self):
if self.prefix.version == 4:
if self.prefix.prefixlen not in [0, 8, 16, 24] and not self.name:
raise ValidationError({
'name': _('Required when prefix length is not 0, 8, 16 or 24'),
})
elif not self.name:
# Generate it for the user
self.name = 'in-addr.arpa'
for pos, octet in enumerate(self.prefix.ip.words):
if pos * 8 >= self.prefix.prefixlen:
break
self.name = f'{octet}.{self.name}'
else:
if self.prefix.prefixlen % 4 != 0 and not self.name:
raise ValidationError({
'name': _('Required when prefix length is not a nibble boundary'),
})
elif not self.name:
# Generate it for the user
self.name = 'ip6.arpa'
nibbles = f'{self.prefix.ip.value:032x}'
for pos, nibble in enumerate(nibbles):
if pos * 4 >= self.prefix.prefixlen:
break
self.name = f'{nibble}.{self.name}'
# Ensure trailing dots from domain-style fields
self.name = normalize_fqdn(self.name)
class DNSStatus(models.Model):
ip_address = models.OneToOneField(
to=IPAddress,
verbose_name=_('IP address'),
on_delete=models.CASCADE,
)
last_update = models.DateTimeField(
verbose_name=_('last update'),
auto_now=True,
)
forward_action = models.PositiveSmallIntegerField(
verbose_name=_('forward record action'),
choices=ACTION_CHOICES,
blank=True,
null=True,
)
forward_rcode = models.PositiveIntegerField(
verbose_name=_('forward record response'),
blank=True,
null=True,
)
reverse_action = models.PositiveSmallIntegerField(
verbose_name=_('reverse record action'),
choices=ACTION_CHOICES,
blank=True,
null=True,
)
reverse_rcode = models.PositiveIntegerField(
verbose_name=_('reverse record response'),
blank=True,
null=True,
)
class Meta:
verbose_name = _('DNS status')
verbose_name_plural = _('DNS status')
def get_forward_rcode_display(self) -> Optional[str]:
return get_rcode_display(self.forward_rcode)
def get_forward_rcode_html_display(self) -> Optional[str]:
output = get_rcode_display(self.forward_rcode)
colour = 'green' if self.forward_rcode == rcode.NOERROR else 'red'
return format_html('<span style="color:{colour}">{output}</span', colour=colour, output=output)
def get_reverse_rcode_display(self) -> Optional[str]:
return get_rcode_display(self.reverse_rcode)
def get_reverse_rcode_html_display(self) -> Optional[str]:
output = get_rcode_display(self.reverse_rcode)
colour = 'green' if self.reverse_rcode == rcode.NOERROR else 'red'
return format_html('<span style="color:{colour}">{output}</span', colour=colour, output=output)
class ExtraDNSName(models.Model):
ip_address = models.ForeignKey(
to=IPAddress,
verbose_name=_('IP address'),
on_delete=models.CASCADE,
)
name = models.CharField(
verbose_name=_('DNS name'),
max_length=255,
validators=[HostnameValidator()],
)
last_update = models.DateTimeField(
verbose_name=_('last update'),
auto_now=True,
)
forward_action = models.PositiveSmallIntegerField(
verbose_name=_('forward record action'),
choices=ACTION_CHOICES,
blank=True,
null=True,
)
forward_rcode = models.PositiveIntegerField(
verbose_name=_('forward record response'),
blank=True,
null=True,
)
before_save = None
class Meta:
unique_together = (
('ip_address', 'name'),
)
verbose_name = _('extra DNS name')
verbose_name_plural = _('extra DNS names')
def __str__(self):
return self.name
def clean(self):
# Ensure trailing dots from domain-style fields
self.name = normalize_fqdn(self.name)
def get_forward_rcode_display(self) -> Optional[str]:
return get_rcode_display(self.forward_rcode)
def get_forward_rcode_html_display(self) -> Optional[str]:
output = get_rcode_display(self.forward_rcode)
colour = 'green' if self.forward_rcode == rcode.NOERROR else 'red'
return format_html('<span style="color:{colour}">{output}</span', colour=colour, output=output)