Bug 1686421 - Add probes to understand how HTTPS RR is used r=necko-reviewers,dragana

Differential Revision: https://phabricator.services.mozilla.com/D101631

netwerk/protocol/http/nsHttpChannel.cpp

@@ -627,7 +627,7 @@ nsresult nsHttpChannel::MaybeUseHTTPSRRForUpgrade(bool aShouldUpgrade,
         this));
     StoreWaitHTTPSSVCRecord(false);
     bool hasHTTPSRR = (mHTTPSSVCRecord.ref() != nullptr);
-    return ContinueOnBeforeConnect(hasHTTPSRR, aStatus);
+    return ContinueOnBeforeConnect(hasHTTPSRR, aStatus, hasHTTPSRR);
   }
 
   LOG(("nsHttpChannel::MaybeUseHTTPSRRForUpgrade [%p] wait for HTTPS RR",
@@ -637,7 +637,8 @@ nsresult nsHttpChannel::MaybeUseHTTPSRRForUpgrade(bool aShouldUpgrade,
 }
 
 nsresult nsHttpChannel::ContinueOnBeforeConnect(bool aShouldUpgrade,
-                                                nsresult aStatus) {
+                                                nsresult aStatus,
+                                                bool aUpgradeWithHTTPSRR) {
   LOG(
       ("nsHttpChannel::ContinueOnBeforeConnect "
        "[this=%p aShouldUpgrade=%d rv=%" PRIx32 "]\n",
@@ -650,6 +651,8 @@ nsresult nsHttpChannel::ContinueOnBeforeConnect(bool aShouldUpgrade,
   }
 
   if (aShouldUpgrade) {
+    Telemetry::Accumulate(Telemetry::HTTPS_UPGRADE_WITH_HTTPS_RR,
+                          aUpgradeWithHTTPSRR);
     return AsyncCall(&nsHttpChannel::HandleAsyncRedirectChannelToHttps);
   }
 
@@ -7563,6 +7566,26 @@ nsresult nsHttpChannel::ContinueOnStartRequest4(nsresult result) {
   return CallOnStartRequest();
 }
 
+static void ReportHTTPSRRTelemetry(
+    const Maybe<nsCOMPtr<nsIDNSHTTPSSVCRecord>>& aMaybeRecord) {
+  bool hasHTTPSRR = aMaybeRecord && (aMaybeRecord.ref() != nullptr);
+  Telemetry::Accumulate(Telemetry::HTTPS_RR_PRESENTED, hasHTTPSRR);
+  if (!hasHTTPSRR) {
+    return;
+  }
+
+  const nsCOMPtr<nsIDNSHTTPSSVCRecord>& record = aMaybeRecord.ref();
+  nsCOMPtr<nsISVCBRecord> svcbRecord;
+  if (NS_SUCCEEDED(record->GetServiceModeRecord(false, false,
+                                                getter_AddRefs(svcbRecord)))) {
+    MOZ_ASSERT(svcbRecord);
+
+    Maybe<Tuple<nsCString, bool>> alpn = svcbRecord->GetAlpn();
+    bool isHttp3 = alpn ? Get<1>(*alpn) : false;
+    Telemetry::Accumulate(Telemetry::HTTPS_RR_WITH_HTTP3_PRESENTED, isHttp3);
+  }
+}
+
 NS_IMETHODIMP
 nsHttpChannel::OnStopRequest(nsIRequest* request, nsresult status) {
   AUTO_PROFILER_LABEL("nsHttpChannel::OnStopRequest", NETWORK);
@@ -7580,6 +7603,12 @@ nsHttpChannel::OnStopRequest(nsIRequest* request, nsresult status) {
     return NS_OK;
   }
 
+  // It's possible that LoadUseHTTPSSVC() is false, but we already have
+  // mHTTPSSVCRecord.
+  if (LoadUseHTTPSSVC() || mHTTPSSVCRecord) {
+    ReportHTTPSRRTelemetry(mHTTPSSVCRecord);
+  }
+
   // If this load failed because of a security error, it may be because we
   // are in a captive portal - trigger an async check to make sure.
   int32_t nsprError = -1 * NS_ERROR_GET_CODE(status);
@@ -9000,7 +9029,7 @@ void nsHttpChannel::OnHTTPSRRAvailable(nsIDNSHTTPSSVCRecord* aRecord) {
     MOZ_ASSERT(mURI->SchemeIs("http"));
 
     StoreWaitHTTPSSVCRecord(false);
-    nsresult rv = ContinueOnBeforeConnect(!!httprr, mStatus);
+    nsresult rv = ContinueOnBeforeConnect(!!httprr, mStatus, !!httprr);
     if (NS_FAILED(rv)) {
       CloseCacheEntry(false);
       Unused << AsyncAbort(rv);

netwerk/protocol/http/nsHttpChannel.h

@@ -332,8 +332,8 @@ class nsHttpChannel final : public HttpBaseChannel,
   [[nodiscard]] nsresult PrepareToConnect();
   void HandleOnBeforeConnect();
   [[nodiscard]] nsresult OnBeforeConnect();
-  [[nodiscard]] nsresult ContinueOnBeforeConnect(bool aShouldUpgrade,
-                                                 nsresult aStatus);
+  [[nodiscard]] nsresult ContinueOnBeforeConnect(
+      bool aShouldUpgrade, nsresult aStatus, bool aUpgradeWithHTTPSRR = false);
   nsresult MaybeUseHTTPSRRForUpgrade(bool aShouldUpgrade, nsresult aStatus);
   void OnHTTPSRRAvailable(nsIDNSHTTPSSVCRecord* aRecord);
   void OnBeforeConnectContinue();

toolkit/components/telemetry/Histograms.json

@@ -16455,5 +16455,32 @@
     "description": "TLS handshake with and without EchConfig success rate.",
     "alert_emails": ["necko@mozilla.com", "kershaw@mozilla.com"],
     "bug_numbers": [1682555]
+  },
+  "HTTPS_RR_PRESENTED": {
+    "record_in_processes": ["main"],
+    "products": ["firefox"],
+    "alert_emails": ["necko@mozilla.com", "kershaw@mozilla.com"],
+    "bug_numbers": [1686421],
+    "expires_in_version": "never",
+    "kind": "boolean",
+    "description": "HTTPS RR is presented or not."
+  },
+  "HTTPS_RR_WITH_HTTP3_PRESENTED": {
+    "record_in_processes": ["main"],
+    "products": ["firefox"],
+    "alert_emails": ["necko@mozilla.com", "kershaw@mozilla.com"],
+    "bug_numbers": [1686421],
+    "expires_in_version": "never",
+    "kind": "boolean",
+    "description": "Whether an HTTPS RR indicates that HTTP3 should be used."
+  },
+  "HTTPS_UPGRADE_WITH_HTTPS_RR": {
+    "record_in_processes": ["main"],
+    "products": ["firefox"],
+    "alert_emails": ["necko@mozilla.com", "kershaw@mozilla.com"],
+    "bug_numbers": [1686421],
+    "expires_in_version": "never",
+    "kind": "boolean",
+    "description": "Whether an HTTP request gets upgraded to HTTPS because HTTPS RR is presented"
   }
 }