dnsdist: Add EDNS to responses generated from raw record data

My reasoning is that it makes sense to add EDNS to responses generated from DNSdist provided that: - the initial query had EDNS - `setAddEDNSToSelfGeneratedResponses` has not been set to `false` - we are only provided part of the response and not a full response packet (cherry picked from commit cae561a)
rgacogne · Sep 30, 2024 · 0fa402a · 0fa402a
1 parent 02338bb
commit 0fa402a
Show file tree

Hide file tree

Showing 2 changed files with 66 additions and 22 deletions.
diff --git a/pdns/dnsdist-lua-actions.cc b/pdns/dnsdist-lua-actions.cc
@@ -934,7 +934,6 @@ DNSAction::Action SpoofAction::operator()(DNSQuestion* dnsquestion, std::string*
   static_assert(recordstart.size() == 12, "sizeof(recordstart) must be equal to 12, otherwise the above check is invalid");
   memcpy(&recordstart[4], &qclass, sizeof(qclass));
   memcpy(&recordstart[6], &ttl, sizeof(ttl));
-  bool raw = false;
 
   if (qtype == QType::CNAME) {
     const auto& wireData = d_cname.getStorage(); // Note! This doesn't do compression!
@@ -975,7 +974,6 @@ DNSAction::Action SpoofAction::operator()(DNSQuestion* dnsquestion, std::string*
         return true;
       });
     }
-    raw = true;
   }
   else {
     for (const auto& addr : addrs) {
@@ -1007,7 +1005,7 @@ DNSAction::Action SpoofAction::operator()(DNSQuestion* dnsquestion, std::string*
     return true;
   });
 
-  if (hadEDNS && !raw) {
+  if (hadEDNS) {
     addEDNS(dnsquestion->getMutableData(), dnsquestion->getMaximumSize(), dnssecOK, g_PayloadSizeSelfGenAnswers, 0);
   }
 

diff --git a/regression-tests.dnsdist/test_Spoofing.py b/regression-tests.dnsdist/test_Spoofing.py
@@ -47,7 +47,33 @@ def testSpoofActionA(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
+
+    def testSpoofActionAWithEDNS(self):
+        """
+        Spoofing: Spoof A via Action (EDNS)
+
+        Send an A query to "spoofaction.spoofing.tests.powerdns.com.",
+        check that dnsdist sends a spoofed result.
+        """
+        name = 'spoofaction.spoofing.tests.powerdns.com.'
+        query = dns.message.make_query(name, 'A', 'IN', use_edns=True)
+        # dnsdist set RA = RD for spoofed responses
+        query.flags &= ~dns.flags.RD
+        expectedResponse = dns.message.make_response(query)
+        expectedResponse.use_edns(edns=True, payload=1232)
+        rrset = dns.rrset.from_text(name,
+                                    60,
+                                    dns.rdataclass.IN,
+                                    dns.rdatatype.A,
+                                    '192.0.2.1')
+        expectedResponse.answer.append(rrset)
+
+        for method in ("sendUDPQuery", "sendTCPQuery"):
+            sender = getattr(self, method)
+            (_, receivedResponse) = sender(query, response=None, useQueue=False)
+            self.assertTrue(receivedResponse)
+            self.checkMessageEDNSWithoutOptions(expectedResponse, receivedResponse)
 
     def testSpoofActionAAAA(self):
         """
@@ -101,7 +127,7 @@ def testSpoofActionCNAME(self):
 
     def testSpoofActionMultiA(self):
         """
-        Spoofing: Spoof multiple IPv4 addresses via AddDomainSpoof
+        Spoofing: Spoof multiple IPv4 addresses
 
         Send an A query for "multispoof.spoofing.tests.powerdns.com.",
         check that dnsdist sends a spoofed result.
@@ -126,7 +152,7 @@ def testSpoofActionMultiA(self):
 
     def testSpoofActionMultiAAAA(self):
         """
-        Spoofing: Spoof multiple IPv6 addresses via AddDomainSpoof
+        Spoofing: Spoof multiple IPv6 addresses
 
         Send an AAAA query for "multispoof.spoofing.tests.powerdns.com.",
         check that dnsdist sends a spoofed result.
@@ -151,7 +177,7 @@ def testSpoofActionMultiAAAA(self):
 
     def testSpoofActionMultiANY(self):
         """
-        Spoofing: Spoof multiple addresses via AddDomainSpoof
+        Spoofing: Spoof multiple addresses
 
         Send an ANY query for "multispoof.spoofing.tests.powerdns.com.",
         check that dnsdist sends a spoofed result.
@@ -320,7 +346,27 @@ def testSpoofRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
+            self.assertEqual(receivedResponse.answer[0].ttl, 60)
+
+        # A with EDNS
+        query = dns.message.make_query(name, 'A', 'IN', use_edns=True)
+        query.flags &= ~dns.flags.RD
+        expectedResponse = dns.message.make_response(query)
+        expectedResponse.use_edns(edns=True, payload=1232)
+        expectedResponse.flags &= ~dns.flags.AA
+        rrset = dns.rrset.from_text(name,
+                                    60,
+                                    dns.rdataclass.IN,
+                                    dns.rdatatype.A,
+                                    '192.0.2.1')
+        expectedResponse.answer.append(rrset)
+
+        for method in ("sendUDPQuery", "sendTCPQuery"):
+            sender = getattr(self, method)
+            (_, receivedResponse) = sender(query, response=None, useQueue=False)
+            self.assertTrue(receivedResponse)
+            self.checkMessageEDNSWithoutOptions(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # TXT
@@ -339,7 +385,7 @@ def testSpoofRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # SRV
@@ -359,7 +405,7 @@ def testSpoofRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 3600)
 
     def testSpoofRawChaosAction(self):
@@ -384,7 +430,7 @@ def testSpoofRawChaosAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
     def testSpoofRawANYAction(self):
@@ -408,7 +454,7 @@ def testSpoofRawANYAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
     def testSpoofRawActionMulti(self):
@@ -433,7 +479,7 @@ def testSpoofRawActionMulti(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # TXT
@@ -452,7 +498,7 @@ def testSpoofRawActionMulti(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
 class TestSpoofingLuaSpoof(DNSDistTest):
@@ -617,7 +663,7 @@ def testLuaSpoofRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # TXT
@@ -636,7 +682,7 @@ def testLuaSpoofRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # SRV
@@ -656,7 +702,7 @@ def testLuaSpoofRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             # sorry, we can't set the TTL from the Lua API right now
             #self.assertEqual(receivedResponse.answer[0].ttl, 3600)
 
@@ -769,7 +815,7 @@ def testLuaSpoofMultiRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # TXT
@@ -788,7 +834,7 @@ def testLuaSpoofMultiRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # SRV
@@ -808,7 +854,7 @@ def testLuaSpoofMultiRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             # sorry, we can't set the TTL from the Lua API right now
             #self.assertEqual(receivedResponse.answer[0].ttl, 3600)
 
@@ -878,7 +924,7 @@ def testLuaSpoofMultiRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
         # TXT
@@ -897,7 +943,7 @@ def testLuaSpoofMultiRawAction(self):
             sender = getattr(self, method)
             (_, receivedResponse) = sender(query, response=None, useQueue=False)
             self.assertTrue(receivedResponse)
-            self.assertEqual(expectedResponse, receivedResponse)
+            self.checkMessageNoEDNS(expectedResponse, receivedResponse)
             self.assertEqual(receivedResponse.answer[0].ttl, 60)
 
 class TestSpoofingLuaWithStatistics(DNSDistTest):