X-Git-Url: http://xvm.mit.edu/gitweb/invirt/packages/invirt-dns.git/blobdiff_plain/8de2c88bc911ba9fe5bc43e003880ddb1e8972b4..5216f3e70aeacc22c2f6afc0f9eac1aa13def2d7:/invirt-dns diff --git a/invirt-dns b/invirt-dns index 24117f0..c6394e6 100755 --- a/invirt-dns +++ b/invirt-dns @@ -45,7 +45,7 @@ class DatabaseAuthority(common.ResolverBase): 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" @@ -63,14 +63,17 @@ class DatabaseAuthority(common.ResolverBase): 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.) + # Look for the longest-matching domain. 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))) + if name.endswith('.in-addr.arpa'): + # Act authoritative for the IP address for reverse resolution requests + best_domain = name + else: + return defer.fail(failure.Failure(dns.DomainError(name))) domain = best_domain results = [] authority = [] @@ -78,52 +81,75 @@ class DatabaseAuthority(common.ResolverBase): 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, + # 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_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)) - 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. - 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: + 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 - 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: + elif name == domain or name == '.'+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] + 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: + authority = [] + additional = [] + return defer.succeed((results, authority, additional)) -class QuotingBindAuthority(authority.BindAuthority): +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 @@ -168,12 +194,38 @@ class QuotingBindAuthority(authority.BindAuthority): L.append(split_line) return filter(None, L) + def _lookup(self, name, cls, type, timeout = None): + maybeDelegate = False + deferredResult = authority.BindAuthority._lookup(self, name, cls, + type, timeout) + # 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 (isinstance(deferredResult.result, failure.Failure) + and '.' in name): + maybeDelegate = True + name = name[name.find('.') + 1 :] + deferredResult = authority.BindAuthority._lookup(self, name, cls, + dns.NS, timeout) + # If we found somewhere to delegate the query to, our _lookup() + # for the NS record resulted in it being in the 'results' section. + # We need to instead return that information in the 'authority' + # section to delegate, and return an empty 'results' section + # (because we didn't find the name we were asked about). We + # leave the 'additional' section as we received it because it + # may contain A records for the DNS server we're delegating to. +# if maybeDelegate and not isinstance(deferredResult.result, +# failure.Failure): +# (nsResults, nsAuthority, nsAdditional) = deferredResult.result +# deferredResult = defer.succeed(([], nsResults, nsAdditional)) + return deferredResult + 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 r.origin = origin