+++ /dev/null
-#!/usr/bin/python
-from twisted.internet import reactor
-from twisted.names import server
-from twisted.names import dns
-from twisted.names import common
-from twisted.internet import defer
-from twisted.python import failure
-
-from invirt.config import structs as config
-import invirt.database
-import psycopg2
-import sqlalchemy
-import time
-
-class DatabaseAuthority(common.ResolverBase):
- """An Authority that is loaded from a file."""
-
- soa = None
-
- def __init__(self, domains=None, database=None):
- common.ResolverBase.__init__(self)
- if database is not None:
- invirt.database.connect(database)
- else:
- invirt.database.connect()
- if domains is not None:
- self.domains = domains
- else:
- self.domains = config.dns.domains
- ns = config.dns.nameservers[0]
- self.soa = dns.Record_SOA(mname=ns.hostname,
- rname=config.dns.contact.replace('@','.',1),
- serial=1, refresh=3600, retry=900,
- expire=3600000, minimum=21600, ttl=3600)
- self.ns = dns.Record_NS(name=ns.hostname, ttl=3600)
- record = dns.Record_A(address=ns.ip, ttl=3600)
- self.ns1 = dns.RRHeader(ns.hostname, dns.A, dns.IN,
- 3600, record, auth=True)
-
-
- def _lookup(self, name, cls, type, timeout = None):
- for i in range(3):
- try:
- value = self._lookup_unsafe(name, cls, type, timeout = None)
- except (psycopg2.OperationalError, sqlalchemy.exceptions.SQLError):
- if i == 2:
- raise
- print "Reloading database"
- time.sleep(0.5)
- continue
- else:
- return value
-
- def _lookup_unsafe(self, name, cls, type, timeout):
- invirt.database.clear_cache()
-
- ttl = 900
- name = name.lower()
-
- # XXX hack for the transition to two separate dev/prod clusters
- if 'dev.xvm.mit.edu' in self.domains and name.endswith('prod.xvm.mit.edu'):
- # import time, sys
- # print time.localtime(), 'handling prod request', name
- # sys.stdout.flush()
-
- # Point the client in the right direction for prod requests.
- authority = dns.RRHeader('prod.xvm.mit.edu', dns.NS, dns.IN, 3600,
- dns.Record_NS(name='ns1.prod.xvm.mit.edu', ttl=3600), auth=True)
- additional = dns.RRHeader('ns1.prod.xvm.mit.edu', dns.A, dns.IN, 3600,
- dns.Record_A(address='18.181.0.221', ttl=3600), auth=True)
- return defer.succeed(([], [authority], [additional]))
-
- if name in self.domains:
- domain = name
- else:
- # Look for the longest-matching domain. (This works because domain
- # will remain bound after breaking out of the loop.)
- best_domain = ''
- for domain in self.domains:
- if name.endswith('.'+domain) and len(domain) > len(best_domain):
- best_domain = domain
- if best_domain == '':
- return defer.fail(failure.Failure(dns.DomainError(name)))
- domain = best_domain
- results = []
- authority = []
- additional = [self.ns1]
- authority.append(dns.RRHeader(domain, dns.NS, dns.IN,
- 3600, self.ns, auth=True))
-
- if cls == dns.IN:
- host = name[:-len(domain)-1]
- if not host: # Request for the domain itself.
- if type in (dns.A, dns.ALL_RECORDS):
- record = dns.Record_A(config.dns.nameservers[0].ip, ttl)
- results.append(dns.RRHeader(name, dns.A, dns.IN,
- ttl, record, auth=True))
- elif type == dns.NS:
- results.append(dns.RRHeader(domain, dns.NS, dns.IN,
- ttl, self.ns, auth=True))
- authority = []
- elif type == dns.SOA:
- results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
- ttl, self.soa, auth=True))
- else: # Request for a subdomain.
- if 'passup' in dir(config.dns) and host in config.dns.passup:
- record = dns.Record_CNAME('%s.%s' % (host, config.dns.parent), ttl)
- return defer.succeed((
- [dns.RRHeader(name, dns.CNAME, dns.IN, ttl, record, auth=True)],
- [], []))
-
- value = invirt.database.Machine.get_by(name=host)
- if value is None or not value.nics:
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
- ip = value.nics[0].ip
- if ip is None: #Deactivated?
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
-
- if type in (dns.A, dns.ALL_RECORDS):
- record = dns.Record_A(ip, ttl)
- results.append(dns.RRHeader(name, dns.A, dns.IN,
- ttl, record, auth=True))
- elif type == dns.SOA:
- results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
- ttl, self.soa, auth=True))
- if len(results) == 0:
- authority = []
- additional = []
- return defer.succeed((results, authority, additional))
- else:
- #Doesn't exist
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
-
-if '__main__' == __name__:
- resolver = DatabaseAuthority()
-
- verbosity = 0
- f = server.DNSServerFactory(authorities=[resolver], verbose=verbosity)
- p = dns.DNSDatagramProtocol(f)
- f.noisy = p.noisy = verbosity
-
- reactor.listenUDP(53, p)
- reactor.listenTCP(53, f)
- reactor.run()
projects / invirt/packages/invirt-dns.git / blobdiff