fix(webconnectivitylte): handle domains w/o A/AAAA records

internal/experiment/webconnectivitylte/analysisclassic.go

@@ -373,7 +373,17 @@ func analysisClassicComputeBlockingAccessible(woa *minipipeline.WebAnalysis, tk
 				return
 			}
 
-			// 5.3. Handle the case where just the probe failed.
+			// 5.3. When the probe says dns_no_answer the control would otherwise say that
+			// we have resolved zero IP addresses for historical reasons. In such a case,
+			// let's pretend that also the control returned dns_no_answer.
+			if entry.Failure.Unwrap() == netxlite.FailureDNSNoAnswer &&
+				!entry.ControlDNSResolvedAddrs.IsNone() &&
+				entry.ControlDNSResolvedAddrs.Unwrap().Len() <= 0 {
+				tk.setWebsiteDown()
+				return
+			}
+
+			// 5.4. Handle the case where just the probe failed.
 			tk.setBlockingString("dns")
 			tk.setHTTPExperimentFailure(entry.Failure)
 			return
@@ -406,9 +416,6 @@ func analysisClassicComputeBlockingAccessible(woa *minipipeline.WebAnalysis, tk
 			tk.setWebsiteDown()
 			return
 		}
-
-		// TODO(bassosimone): we should handle the case where a domain
-		// exists but there aren't IP addresses for it.
 	}
 }
 

internal/experiment/webconnectivityqa/testcase.go

@@ -88,6 +88,7 @@ func AllTestCases() []*TestCase {
 		tlsBlockingConnectionResetWithInconsistentDNS(),
 
 		websiteDownNXDOMAIN(),
+		websiteDownNoAddrs(),
 		websiteDownTCPConnect(),
 	}
 }

internal/experiment/webconnectivityqa/websitedown.go

@@ -1,5 +1,7 @@
 package webconnectivityqa
 
+import "github.com/ooni/probe-cli/v3/internal/netemx"
+
 // websiteDownNXDOMAIN describes the test case where the website domain
 // is NXDOMAIN according to the TH and the probe.
 func websiteDownNXDOMAIN() *TestCase {
@@ -60,3 +62,29 @@ func websiteDownTCPConnect() *TestCase {
 		},
 	}
 }
+
+// websiteDownNoAddrs describes the test case where the website domain
+// does not return any address according to the TH and the probe.
+func websiteDownNoAddrs() *TestCase {
+	return &TestCase{
+		Name:  "websiteDownNoAddrs",
+		Flags: TestCaseFlagNoV04,
+		Input: "http://www.example.com/",
+		Configure: func(env *netemx.QAEnv) {
+
+			// reconfigure with only CNAME but no addresses and do this
+			// for all the resolvers of the kingdom
+			env.AddRecordToAllResolvers("www.example.com", "web01.example.com" /* No addrs */)
+
+		},
+		ExpectErr: false,
+		ExpectTestKeys: &testKeys{
+			DNSExperimentFailure: "dns_no_answer",
+			DNSConsistency:       "consistent",
+			XBlockingFlags:       0,
+			XNullNullFlags:       1, // AnalysisFlagNullNullExpectedDNSLookupFailure
+			Accessible:           false,
+			Blocking:             false,
+		},
+	}
+}

internal/minipipeline/analysis.go

@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"github.com/ooni/probe-cli/v3/internal/model"
+	"github.com/ooni/probe-cli/v3/internal/netxlite"
 	"github.com/ooni/probe-cli/v3/internal/optional"
 	"github.com/ooni/probe-cli/v3/internal/runtimex"
 )
@@ -449,7 +450,17 @@ func (wa *WebAnalysis) dnsComputeFailureMetrics(c *WebObservationsContainer) {
 		}
 
 		// handle the case where only the probe failed
-		if obs.DNSLookupFailure.Unwrap() != "" {
+		if failure := obs.DNSLookupFailure.Unwrap(); failure != "" {
+			// When the probe says dns_no_answer the control would otherwise say that
+			// we have resolved zero IP addresses for historical reasons. In such a case,
+			// let's pretend that also the control returned dns_no_answer.
+			if failure == netxlite.FailureDNSNoAnswer {
+				if !obs.ControlDNSResolvedAddrs.IsNone() && obs.ControlDNSResolvedAddrs.Unwrap().Len() <= 0 {
+					wa.DNSLookupExpectedFailure.Add(obs.DNSTransactionID.Unwrap())
+					continue
+				}
+				// fallthrough
+			}
 			wa.DNSLookupUnexpectedFailure.Add(obs.DNSTransactionID.Unwrap())
 			continue
 		}

internal/minipipeline/testdata/webconnectivity/generated/websiteDownNoAddrs/analysis.json

@@ -0,0 +1,261 @@
+{
+  "ControlExpectations": {
+    "DNSAddresses": [],
+    "FinalResponseFailure": "dns_lookup_error"
+  },
+  "DNSLookupSuccess": [],
+  "DNSLookupSuccessWithInvalidAddresses": [],
+  "DNSLookupSuccessWithValidAddress": [],
+  "DNSLookupSuccessWithBogonAddresses": [],
+  "DNSLookupSuccessWithInvalidAddressesClassic": [],
+  "DNSLookupSuccessWithValidAddressClassic": [],
+  "DNSLookupUnexpectedFailure": [],
+  "DNSLookupUnexplainedFailure": [],
+  "DNSExperimentFailure": "dns_no_answer",
+  "DNSLookupExpectedFailure": [
+    2,
+    3
+  ],
+  "DNSLookupExpectedSuccess": [],
+  "TCPConnectExpectedFailure": [],
+  "TCPConnectUnexpectedFailure": [],
+  "TCPConnectUnexpectedFailureDuringWebFetch": [],
+  "TCPConnectUnexpectedFailureDuringConnectivityCheck": [],
+  "TCPConnectUnexplainedFailure": [],
+  "TCPConnectUnexplainedFailureDuringWebFetch": [],
+  "TCPConnectUnexplainedFailureDuringConnectivityCheck": [],
+  "TLSHandshakeExpectedFailure": [],
+  "TLSHandshakeUnexpectedFailure": [],
+  "TLSHandshakeUnexpectedFailureDuringWebFetch": [],
+  "TLSHandshakeUnexpectedFailureDuringConnectivityCheck": [],
+  "TLSHandshakeUnexplainedFailure": [],
+  "TLSHandshakeUnexplainedFailureDuringWebFetch": [],
+  "TLSHandshakeUnexplainedFailureDuringConnectivityCheck": [],
+  "HTTPRoundTripUnexpectedFailure": [],
+  "HTTPRoundTripUnexplainedFailure": [],
+  "HTTPFinalResponseSuccessTLSWithoutControl": null,
+  "HTTPFinalResponseSuccessTLSWithControl": null,
+  "HTTPFinalResponseSuccessTCPWithoutControl": null,
+  "HTTPFinalResponseSuccessTCPWithControl": null,
+  "HTTPFinalResponseDiffBodyProportionFactor": null,
+  "HTTPFinalResponseDiffStatusCodeMatch": null,
+  "HTTPFinalResponseDiffTitleDifferentLongWords": null,
+  "HTTPFinalResponseDiffUncommonHeadersIntersection": null,
+  "Linear": [
+    {
+      "TagDepth": 0,
+      "Type": 0,
+      "Failure": "dns_no_answer",
+      "TransactionID": 3,
+      "TagFetchBody": null,
+      "DNSTransactionID": 3,
+      "DNSDomain": "www.example.com",
+      "DNSLookupFailure": "dns_no_answer",
+      "DNSQueryType": "A",
+      "DNSEngine": "udp",
+      "DNSResolvedAddrs": null,
+      "IPAddressOrigin": null,
+      "IPAddress": null,
+      "IPAddressASN": null,
+      "IPAddressBogon": null,
+      "EndpointTransactionID": null,
+      "EndpointProto": null,
+      "EndpointPort": null,
+      "EndpointAddress": null,
+      "TCPConnectFailure": null,
+      "TLSHandshakeFailure": null,
+      "TLSServerName": null,
+      "HTTPRequestURL": null,
+      "HTTPFailure": null,
+      "HTTPResponseStatusCode": null,
+      "HTTPResponseBodyLength": null,
+      "HTTPResponseBodyIsTruncated": null,
+      "HTTPResponseHeadersKeys": null,
+      "HTTPResponseLocation": null,
+      "HTTPResponseTitle": null,
+      "HTTPResponseIsFinal": null,
+      "ControlDNSDomain": "www.example.com",
+      "ControlDNSLookupFailure": "",
+      "ControlDNSResolvedAddrs": [],
+      "ControlTCPConnectFailure": null,
+      "ControlTLSHandshakeFailure": null,
+      "ControlHTTPFailure": "dns_lookup_error",
+      "ControlHTTPResponseStatusCode": null,
+      "ControlHTTPResponseBodyLength": null,
+      "ControlHTTPResponseHeadersKeys": null,
+      "ControlHTTPResponseTitle": null
+    },
+    {
+      "TagDepth": 0,
+      "Type": 0,
+      "Failure": "dns_no_answer",
+      "TransactionID": 3,
+      "TagFetchBody": null,
+      "DNSTransactionID": 3,
+      "DNSDomain": "www.example.com",
+      "DNSLookupFailure": "dns_no_answer",
+      "DNSQueryType": "AAAA",
+      "DNSEngine": "udp",
+      "DNSResolvedAddrs": null,
+      "IPAddressOrigin": null,
+      "IPAddress": null,
+      "IPAddressASN": null,
+      "IPAddressBogon": null,
+      "EndpointTransactionID": null,
+      "EndpointProto": null,
+      "EndpointPort": null,
+      "EndpointAddress": null,
+      "TCPConnectFailure": null,
+      "TLSHandshakeFailure": null,
+      "TLSServerName": null,
+      "HTTPRequestURL": null,
+      "HTTPFailure": null,
+      "HTTPResponseStatusCode": null,
+      "HTTPResponseBodyLength": null,
+      "HTTPResponseBodyIsTruncated": null,
+      "HTTPResponseHeadersKeys": null,
+      "HTTPResponseLocation": null,
+      "HTTPResponseTitle": null,
+      "HTTPResponseIsFinal": null,
+      "ControlDNSDomain": "www.example.com",
+      "ControlDNSLookupFailure": "",
+      "ControlDNSResolvedAddrs": [],
+      "ControlTCPConnectFailure": null,
+      "ControlTLSHandshakeFailure": null,
+      "ControlHTTPFailure": "dns_lookup_error",
+      "ControlHTTPResponseStatusCode": null,
+      "ControlHTTPResponseBodyLength": null,
+      "ControlHTTPResponseHeadersKeys": null,
+      "ControlHTTPResponseTitle": null
+    },
+    {
+      "TagDepth": 0,
+      "Type": 0,
+      "Failure": "dns_no_answer",
+      "TransactionID": 2,
+      "TagFetchBody": null,
+      "DNSTransactionID": 2,
+      "DNSDomain": "www.example.com",
+      "DNSLookupFailure": "dns_no_answer",
+      "DNSQueryType": "ANY",
+      "DNSEngine": "getaddrinfo",
+      "DNSResolvedAddrs": null,
+      "IPAddressOrigin": null,
+      "IPAddress": null,
+      "IPAddressASN": null,
+      "IPAddressBogon": null,
+      "EndpointTransactionID": null,
+      "EndpointProto": null,
+      "EndpointPort": null,
+      "EndpointAddress": null,
+      "TCPConnectFailure": null,
+      "TLSHandshakeFailure": null,
+      "TLSServerName": null,
+      "HTTPRequestURL": null,
+      "HTTPFailure": null,
+      "HTTPResponseStatusCode": null,
+      "HTTPResponseBodyLength": null,
+      "HTTPResponseBodyIsTruncated": null,
+      "HTTPResponseHeadersKeys": null,
+      "HTTPResponseLocation": null,
+      "HTTPResponseTitle": null,
+      "HTTPResponseIsFinal": null,
+      "ControlDNSDomain": "www.example.com",
+      "ControlDNSLookupFailure": "",
+      "ControlDNSResolvedAddrs": [],
+      "ControlTCPConnectFailure": null,
+      "ControlTLSHandshakeFailure": null,
+      "ControlHTTPFailure": "dns_lookup_error",
+      "ControlHTTPResponseStatusCode": null,
+      "ControlHTTPResponseBodyLength": null,
+      "ControlHTTPResponseHeadersKeys": null,
+      "ControlHTTPResponseTitle": null
+    },
+    {
+      "TagDepth": 0,
+      "Type": 0,
+      "Failure": "dns_nxdomain_error",
+      "TransactionID": 1,
+      "TagFetchBody": null,
+      "DNSTransactionID": 1,
+      "DNSDomain": "www.example.com",
+      "DNSLookupFailure": "dns_nxdomain_error",
+      "DNSQueryType": "AAAA",
+      "DNSEngine": "doh",
+      "DNSResolvedAddrs": null,
+      "IPAddressOrigin": null,
+      "IPAddress": null,
+      "IPAddressASN": null,
+      "IPAddressBogon": null,
+      "EndpointTransactionID": null,
+      "EndpointProto": null,
+      "EndpointPort": null,
+      "EndpointAddress": null,
+      "TCPConnectFailure": null,
+      "TLSHandshakeFailure": null,
+      "TLSServerName": null,
+      "HTTPRequestURL": null,
+      "HTTPFailure": null,
+      "HTTPResponseStatusCode": null,
+      "HTTPResponseBodyLength": null,
+      "HTTPResponseBodyIsTruncated": null,
+      "HTTPResponseHeadersKeys": null,
+      "HTTPResponseLocation": null,
+      "HTTPResponseTitle": null,
+      "HTTPResponseIsFinal": null,
+      "ControlDNSDomain": "www.example.com",
+      "ControlDNSLookupFailure": "",
+      "ControlDNSResolvedAddrs": [],
+      "ControlTCPConnectFailure": null,
+      "ControlTLSHandshakeFailure": null,
+      "ControlHTTPFailure": "dns_lookup_error",
+      "ControlHTTPResponseStatusCode": null,
+      "ControlHTTPResponseBodyLength": null,
+      "ControlHTTPResponseHeadersKeys": null,
+      "ControlHTTPResponseTitle": null
+    },
+    {
+      "TagDepth": 0,
+      "Type": 0,
+      "Failure": "dns_nxdomain_error",
+      "TransactionID": 1,
+      "TagFetchBody": null,
+      "DNSTransactionID": 1,
+      "DNSDomain": "www.example.com",
+      "DNSLookupFailure": "dns_nxdomain_error",
+      "DNSQueryType": "A",
+      "DNSEngine": "doh",
+      "DNSResolvedAddrs": null,
+      "IPAddressOrigin": null,
+      "IPAddress": null,
+      "IPAddressASN": null,
+      "IPAddressBogon": null,
+      "EndpointTransactionID": null,
+      "EndpointProto": null,
+      "EndpointPort": null,
+      "EndpointAddress": null,
+      "TCPConnectFailure": null,
+      "TLSHandshakeFailure": null,
+      "TLSServerName": null,
+      "HTTPRequestURL": null,
+      "HTTPFailure": null,
+      "HTTPResponseStatusCode": null,
+      "HTTPResponseBodyLength": null,
+      "HTTPResponseBodyIsTruncated": null,
+      "HTTPResponseHeadersKeys": null,
+      "HTTPResponseLocation": null,
+      "HTTPResponseTitle": null,
+      "HTTPResponseIsFinal": null,
+      "ControlDNSDomain": "www.example.com",
+      "ControlDNSLookupFailure": "",
+      "ControlDNSResolvedAddrs": [],
+      "ControlTCPConnectFailure": null,
+      "ControlTLSHandshakeFailure": null,
+      "ControlHTTPFailure": "dns_lookup_error",
+      "ControlHTTPResponseStatusCode": null,
+      "ControlHTTPResponseBodyLength": null,
+      "ControlHTTPResponseHeadersKeys": null,
+      "ControlHTTPResponseTitle": null
+    }
+  ]
+}