from twisted.names import dns
from twisted.names import common
from twisted.names import authority
+from twisted.names import resolve
from twisted.internet import defer
from twisted.python import failure
from invirt.common import InvirtConfigError
from invirt.config import structs as config
import invirt.database
+from invirt.database import NIC
import psycopg2
import sqlalchemy
import time
import re
+import sys
class DatabaseAuthority(common.ResolverBase):
"""An Authority that is loaded from a file."""
for i in range(3):
try:
value = self._lookup_unsafe(name, cls, type, timeout = None)
- except (psycopg2.OperationalError, sqlalchemy.exceptions.SQLError):
+ except (psycopg2.OperationalError, sqlalchemy.exceptions.DBAPIError):
if i == 2:
raise
print "Reloading database"
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 and type != dns.PTR: # 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,
+ # The order of logic:
+ # - What class?
+ # - What domain: in-addr.arpa, domain root, or subdomain?
+ # - What query type: A, PTR, NS, ...?
+
+ if cls != dns.IN:
+ # Hahaha. No.
+ return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+
+ if name.endswith(".in-addr.arpa"):
+ if type in (dns.PTR, dns.ALL_RECORDS):
+ ip = '.'.join(reversed(name.split('.')[:-2]))
+ value = invirt.database.NIC.query.filter((NIC.ip == ip) | (NIC.other_ip == ip)).first()
+ if value and value.hostname:
+ hostname = value.hostname
+ if '.' not in hostname:
+ if ip == value.other_ip:
+ hostname = hostname + ".other"
+ hostname = hostname + "." + config.dns.domains[0]
+ record = dns.Record_PTR(hostname, ttl)
+ results.append(dns.RRHeader(name, dns.PTR, 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 name.endswith(".in-addr.arpa"): # Reverse resolution here
- if type in (dns.PTR, dns.ALL_RECORDS):
- ip = '.'.join(reversed(name.split('.')[:-2]))
- value = invirt.database.NIC.query.filter_by(ip=ip).first()
- if value and value.hostname:
- hostname = value.hostname
- if '.' not in hostname:
- hostname = hostname + "." + config.dns.domains[0]
- record = dns.Record_PTR(hostname, ttl)
- results.append(dns.RRHeader(name, dns.PTR, dns.IN,
- ttl, record, auth=True))
- else: # IP address doesn't point to an active host
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
- # FIXME: Should only return success with no records if the name actually exists
- else: # Forward resolution here
- value = invirt.database.NIC.query.filter_by(hostname=host).first()
- if value:
- ip = value.ip
- else:
- value = invirt.database.Machine.query().filter_by(name=host).first()
- if value:
- ip = value.nics[0].ip
- else:
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
-
- if ip is None:
- 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:
+ else: # IP address doesn't point to an active host
+ return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+ elif type == dns.SOA:
+ results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
+ ttl, self.soa, auth=True))
+ # FIXME: Should only return success with no records if the name actually exists
+
+ elif name == domain or name == '.'+domain or name == 'other.'+domain:
+ 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 = []
- additional = []
- return defer.succeed((results, authority, additional))
+ elif type == dns.SOA:
+ results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
+ ttl, self.soa, auth=True))
+
else:
- #Doesn't exist
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+ host = name[:-len(domain)-1]
+ other = False
+ if host.endswith(".other"):
+ host = host[:-len(".other")]
+ other = True
+ value = invirt.database.NIC.query.filter_by(hostname=host).first()
+ if value:
+ if other:
+ ip = value.other_ip
+ action = value.other_action
+ else:
+ ip = value.ip
+ else:
+ value = invirt.database.Machine.query.filter_by(name=host).first()
+ if value:
+ if other:
+ ip = value.nics[0].other_ip
+ action = value.nics[0].other_action
+ else:
+ ip = value.nics[0].ip
+ else:
+ return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+ if ip is None:
+ 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))
+ if other and type in (dns.TXT, dns.ALL_RECORDS):
+ record = dns.Record_TXT(action if action else '', ttl=ttl)
+ results.append(dns.RRHeader(name, dns.TXT, dns.IN,
+ ttl, record, auth=True))
+ if type == dns.SOA:
+ results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
+ ttl, self.soa, auth=True))
-class QuotingBindAuthority(authority.BindAuthority):
+ if len(results) == 0:
+ authority = []
+ additional = []
+ return defer.succeed((results, authority, additional))
+
+class DelegatingQuotingBindAuthority(authority.BindAuthority):
"""
- A BindAuthority that (almost) deals with quoting correctly
+ A delegating BindAuthority that (almost) deals with quoting correctly
This will catch double quotes as marking the start or end of a
quoted phrase, unless the double quote is escaped by a backslash
L.append(split_line)
return filter(None, L)
+ # See https://twistedmatrix.com/documents/13.1.0/api/twisted.internet.defer.html#inlineCallbacks
+ @defer.inlineCallbacks
+ def _lookup(self, name, cls, type, timeout = None):
+ try:
+ result = yield authority.BindAuthority._lookup(self, name, cls,
+ type, timeout)
+ defer.returnValue(result)
+ except Exception as e:
+ # XXX: Twisted returns DomainError even if it is
+ # authoritative for the domain because our SOA record
+ # incorrectly contains (origin + "." + origin)
+ if not isinstance(e, (dns.DomainError, dns.AuthoritativeDomainError)):
+ sys.stderr.write("while looking up '%s', got: %s\n" % (name, e))
+
+ # If we didn't find an exact match for the name we were
+ # seeking, check if it's within a subdomain we're supposed
+ # to delegate to some other DNS server.
+ while '.' in name:
+ _, name = name.split('.', 1)
+ try:
+ # BindAuthority puts the NS in the authority
+ # section automatically for us, so just return
+ # it. We override the type to NS.
+ result = yield authority.BindAuthority._lookup(self, name, cls,
+ dns.NS, timeout)
+ defer.returnValue(result)
+ except Exception: # Should be one of (dns.DomainError, dns.AuthoritativeDomainError)
+ pass
+ # We didn't find a delegation, so return the original
+ # NXDOMAIN.
+ raise
+
+class TypeLenientResolverChain(resolve.ResolverChain):
+ """
+ This is a ResolverChain which is more lenient in its handling of
+ queries requesting unimplemented record types.
+ """
+
+ def query(self, query, timeout = None):
+ try:
+ return self.typeToMethod[query.type](str(query.name), timeout)
+ except KeyError, e:
+ # We don't support the requested record type. Twisted would
+ # have us return SERVFAIL. Instead, we'll check whether the
+ # name exists in our zone at all and return NXDOMAIN or an empty
+ # result set with NOERROR as appropriate.
+ deferredResult = self.lookupAllRecords(str(query.name), timeout)
+ if isinstance(deferredResult.result, failure.Failure):
+ return deferredResult
+ return defer.succeed(([], [], []))
+
if '__main__' == __name__:
resolvers = []
try:
for zone in config.dns.zone_files:
for origin in config.dns.domains:
- r = QuotingBindAuthority(zone)
+ r = DelegatingQuotingBindAuthority(zone)
# This sucks, but if I want a generic zone file, I have to
# reload the information by hand
+ # XXX: This causes our SOA record to contain
+ # (origin + "." + origin)
+ # As a result the resolver never believes it is authoritative.
r.origin = origin
lines = open(zone).readlines()
lines = r.collapseContinuations(r.stripComments(lines))
resolvers.append(DatabaseAuthority())
verbosity = 0
- f = server.DNSServerFactory(authorities=resolvers, verbose=verbosity)
+ f = server.DNSServerFactory(verbose=verbosity)
+ f.resolver = TypeLenientResolverChain(resolvers)
p = dns.DNSDatagramProtocol(f)
f.noisy = p.noisy = verbosity
projects / invirt/packages/invirt-dns.git / blobdiff