yadyn/server/DnsHandler.py

77 lines
2.8 KiB
Python

import dns
import dns.query
import dns.update
import dns.rdataclass
import dns.rdatatype
import dns.rdtypes.IN.A
import dns.tsigkeyring
from dns.tsig import HMAC_SHA256
import dns.rcode
import threading
import time
from logger import Logger
class LocalDnsHandlerException(Exception):
def __init__(self, msg):
Exception.__init__(self, msg)
class DnsHandler(threading.Thread):
def __init__(self, msgQueue, dnsDummy, tsigKey, nsAddress, nsPort, ttl, actionlogDir):
threading.Thread.__init__(self)
self.msgQueue = msgQueue
self.dnsDummy = dnsDummy
self.nsAddress = nsAddress
self.nsPort = nsPort
self.ttl = ttl
self.keyring = dns.tsigkeyring.from_text(tsigKey)
self.actionlogDir = actionlogDir
self.setDaemon(True)
def writeActionlog(self, dynid, name, zone, oldAddr, newAddr):
f = open("%s/%s" % (self.actionlogDir, dynid), 'a')
f.write("%d %s.%s %s %s\n" % (time.time(), name, zone, oldAddr, newAddr))
f.close()
def run(self):
while(True):
msg = self.msgQueue.get()
if msg.address != msg.addressInDns:
try:
self.deleteARR(msg.dynid, msg.name, msg.zone)
self.insertARR(msg.dynid, msg.name, msg.zone, msg.address)
self.writeActionlog(msg.dynid, msg.name, msg.zone, msg.addressInDns, msg.address)
Logger.log("Update: %s, %s.%s, %s -> %s" %
(msg.dynid, msg.name, msg.zone, msg.addressInDns, msg.address))
msg.addressInDns = msg.address
except Exception, e:
Logger.log("Failure for %s when updating DNS: %s" % (str(msg), str(e)))
def insertARR(self, dynid, name, zone, address):
if self.dnsDummy:
return
# send A-RR insertion for ip to DNS server
rr = dns.rdtypes.IN.A.A(dns.rdataclass.IN, dns.rdatatype.A, address)
u = dns.update.Update(zone, keyring=self.keyring, keyalgorithm=HMAC_SHA256)
u.add(name, self.ttl, rr)
r = dns.query.tcp(u, self.nsAddress, port=self.nsPort)
rc = r.rcode()
if rc != 0:
raise LocalDnsHandlerException("failure when inserting: %d, %s" % (rc, dns.rcode.to_text(rc)))
def deleteARR(self, dynid, name, zone):
if self.dnsDummy:
return
# send A-RR deletion for ip to DNS server
u = dns.update.Update(zone, keyring=self.keyring, keyalgorithm=HMAC_SHA256)
u.delete(name)
r = dns.query.tcp(u, self.nsAddress, port=self.nsPort)
rc = r.rcode()
if rc != 0:
raise LocalDnsHandlerException("failure when deleting: %d, %s" % (rc, dns.rcode.to_text(rc)))