Restructuring code to correctly return NXDOMAIN on non-A-record requests

[invirt/packages/invirt-dns.git] / code / dnsserver.py

diff --git a/code/dnsserver.py b/code/dnsserver.py
index 08cf979..7678db5 100755 (executable)
--- a/code/dnsserver.py
+++ b/code/dnsserver.py
@@ -25,6 +25,12 @@ class DatabaseAuthority(common.ResolverBase):
                                   rname='sipb-xen.mit.edu',
                                   serial=1, refresh=3600, retry=900,
                                   expire=3600000, minimum=21600, ttl=3600)
+        self.ns = dns.Record_NS(name='ns1.xvm.mit.edu', ttl=3600)
+        record = dns.Record_A(address='18.181.0.62', ttl=3600)
+        self.ns1 = dns.RRHeader('ns1.xvm.mit.edu', dns.A, dns.IN,
+                                3600, record, auth=True)
+
+    
     def _lookup(self, name, cls, type, timeout = None):
         for i in range(3):
             try:
@@ -40,40 +46,59 @@ class DatabaseAuthority(common.ResolverBase):
 
     def _lookup_unsafe(self, name, cls, type, timeout):
         sipb_xen_database.clear_cache()
-        if name.lower() in self.domains:
-            domain = name.lower()
+        
+        ttl = 900
+        name = name.lower()
+        if name in self.domains:
+            domain = name
         else:
+            # This works because domain will remain bound after breaking out of the loop
             for domain in self.domains:
-                if name.lower().endswith('.'+domain):
+                if name.endswith('.'+domain):
                     break
             else: #Not us
                 return defer.fail(failure.Failure(dns.DomainError(name)))
         results = []
-        if cls == dns.IN and type in (dns.A, dns.ALL_RECORDS):
+        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:
-                ttl = 900
-                record = dns.Record_CNAME('sipb-xen-dev.mit.edu', ttl)
-                results.append(dns.RRHeader(name, dns.CNAME, dns.IN, 
-                                            ttl, record, auth=True))
+                if type in (dns.A, dns.ALL_RECORDS):
+                    record = dns.Record_A('18.181.0.62', 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:
-                value = sipb_xen_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)))
-                ttl = 900
-                record = dns.Record_A(ip, ttl)
-                results.append(dns.RRHeader(name, dns.A, dns.IN, 
-                                            ttl, record, auth=True))
-        authority = []
-        auth_record = dns.Record_NS(name='ns1.xvm.mit.edu', ttl=3600)
-        authority.append(dns.RRHeader(domain, dns.NS, dns.IN,
-                                      3600, auth_record, auth=True))
-        return defer.succeed((results, authority, []))
-        #Doesn't exist
-        return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+                if host:
+                    value = sipb_xen_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(['servers.csail.mit.edu',