DNS server configurable via http

dns-http

# http://notmysock.org/blog/hacks/a-twisted-dns-story.html
# http://blog.inneoin.org/2009/11/i-used-twisted-to-create-dns-server.html
# twistd -y dns.py
import socket
 
from twisted.internet import reactor
from twisted.names import dns
from twisted.names import client, server
from twisted.web.server import Site
import klein
from klein import route

class Hosts(object):
    values = {}

@route('/', methods=['POST'])
def set_a_record(request):
    host = request.args['host'][0].strip()
    ip = request.args['ip'][0].strip()
    Hosts.values[host] = ip
    return 'Change accepted'
 
class DNSServerFactory(server.DNSServerFactory):
    def gotResolverResponse(self, (ans, auth, add), protocol, message, address):
        qname = message.queries[0].name.name.lower().strip()
        ip = Hosts.values.get(qname)
        if ip is not None:
            for answer in ans:
                if answer.type != dns.A:
                    continue
                if qname not in answer.name.name:
                    continue
    
                answer.payload.address = socket.inet_aton(ip)
                answer.payload.ttl = 3600
 
        args = (self, (ans, auth, add), protocol, message, address)
        return server.DNSServerFactory.gotResolverResponse(*args)
 
 
verbosity = 0
 
resolver = client.Resolver(servers=[('8.8.8.8', 53)])
factory = DNSServerFactory(clients=[resolver], verbose=verbosity)
protocol = dns.DNSDatagramProtocol(factory)
factory.noisy = protocol.noisy = verbosity
 
reactor.listenUDP(53, protocol, interface="10.20.76.46")
reactor.listenTCP(53, factory, interface="10.20.76.46")
reactor.listenTCP(8232, Site(klein.resource()), interface="127.0.0.1")
reactor.run()