Bug 1689987 - P4: Add a telemetry probe to collect channel success rate when ODoH is used r=necko-reviewers,valentin

Differential Revision: https://phabricator.services.mozilla.com/D105214

netwerk/dns/ChildDNSService.cpp

@@ -44,6 +44,7 @@ already_AddRefed<ChildDNSService> ChildDNSService::GetSingleton() {
       return nullptr;
     }
     gChildDNSService = new ChildDNSService();
+    gChildDNSService->Init();
     ClearOnShutdown(&gChildDNSService);
   }
 
@@ -53,9 +54,7 @@ already_AddRefed<ChildDNSService> ChildDNSService::GetSingleton() {
 NS_IMPL_ISUPPORTS(ChildDNSService, nsIDNSService, nsPIDNSService, nsIObserver)
 
 ChildDNSService::ChildDNSService()
-    : mFirstTime(true),
-      mDisablePrefetch(false),
-      mPendingRequestsLock("DNSPendingRequestsLock") {
+    : mPendingRequestsLock("DNSPendingRequestsLock") {
   MOZ_ASSERT_IF(nsIOService::UseSocketProcess(),
                 XRE_IsContentProcess() || XRE_IsParentProcess());
   MOZ_ASSERT_IF(!nsIOService::UseSocketProcess(),
@@ -332,6 +331,14 @@ ChildDNSService::GetMyHostName(nsACString& result) {
   return NS_ERROR_NOT_AVAILABLE;
 }
 
+NS_IMETHODIMP
+ChildDNSService::GetODoHActivated(bool* aResult) {
+  NS_ENSURE_ARG(aResult);
+
+  *aResult = mODoHActivated;
+  return NS_OK;
+}
+
 void ChildDNSService::NotifyRequestDone(DNSRequestSender* aDnsRequest) {
   // We need the original flags and listener for the pending requests hash.
   uint32_t originalFlags = aDnsRequest->mFlags & ~RESOLVE_OFFLINE;
@@ -385,6 +392,12 @@ nsresult ChildDNSService::Init() {
       // If a manual proxy is in use, disable prefetch implicitly
       prefs->AddObserver("network.proxy.type", this, false);
     }
+
+    nsCOMPtr<nsIObserverService> observerService =
+        mozilla::services::GetObserverService();
+    if (observerService) {
+      observerService->AddObserver(this, "odoh-service-activated", false);
+    }
   }
 
   mDisablePrefetch =
@@ -433,12 +446,13 @@ ChildDNSService::ResetExcludedSVCDomainName(const nsACString& aOwnerName) {
 NS_IMETHODIMP
 ChildDNSService::Observe(nsISupports* subject, const char* topic,
                          const char16_t* data) {
-  // we are only getting called if a preference has changed.
-  NS_ASSERTION(strcmp(topic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) == 0,
-               "unexpected observe call");
+  if (!strcmp(topic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID)) {
+    // Reread prefs
+    Init();
+  } else if (!strcmp(topic, "odoh-service-activated")) {
+    mODoHActivated = u"true"_ns.Equals(data);
+  }
 
-  // Reread prefs
-  Init();
   return NS_OK;
 }
 

netwerk/dns/ChildDNSService.h

@@ -53,8 +53,9 @@ class ChildDNSService final : public nsPIDNSService, public nsIObserver {
       nsIDNSResolverInfo* aResolver, nsIDNSListener* aListener,
       nsresult aReason, const OriginAttributes& aOriginAttributes);
 
-  bool mFirstTime;
-  bool mDisablePrefetch;
+  bool mFirstTime = true;
+  bool mDisablePrefetch = false;
+  bool mODoHActivated = false;
 
   // We need to remember pending dns requests to be able to cancel them.
   nsClassHashtable<nsCStringHashKey, nsTArray<RefPtr<DNSRequestSender>>>

netwerk/dns/ODoHService.cpp

@@ -5,11 +5,13 @@
 
 #include "ODoHService.h"
 
+#include "mozilla/net/SocketProcessChild.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/StaticPrefs_network.h"
 #include "nsIDNSService.h"
 #include "nsIDNSByTypeRecord.h"
 #include "nsIOService.h"
+#include "nsIObserverService.h"
 #include "ODoH.h"
 #include "TRRService.h"
 #include "nsURLHelper.h"
@@ -241,6 +243,31 @@ ODoHService::OnLookupComplete(nsICancelable* aRequest, nsIDNSRecord* aRec,
   mODoHConfigs.reset();
   mODoHConfigs.emplace(std::move(configs));
 
+  // Let observers know whether ODoHService is activated or not.
+  bool hasODoHConfigs = !mODoHConfigs->IsEmpty();
+  auto task = [hasODoHConfigs]() {
+    MOZ_ASSERT(NS_IsMainThread());
+    if (XRE_IsSocketProcess()) {
+      SocketProcessChild::GetSingleton()->SendODoHServiceActivated(
+          hasODoHConfigs);
+    }
+
+    nsCOMPtr<nsIObserverService> observerService =
+        mozilla::services::GetObserverService();
+
+    if (observerService) {
+      observerService->NotifyObservers(nullptr, "odoh-service-activated",
+                                       hasODoHConfigs ? u"true" : u"false");
+    }
+  };
+
+  if (NS_IsMainThread()) {
+    task();
+  } else {
+    NS_DispatchToMainThread(
+        NS_NewRunnableFunction("ODoHService::Activated", std::move(task)));
+  }
+
   if (!mPendingRequests.IsEmpty()) {
     nsTArray<RefPtr<ODoH>> requests = std::move(mPendingRequests);
     nsCOMPtr<nsIEventTarget> target = gTRRService->MainThreadOrTRRThread();

netwerk/dns/nsDNSService2.cpp

@@ -777,6 +777,7 @@ nsDNSService::Init() {
     observerService->AddObserver(this, "last-pb-context-exited", false);
     observerService->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
     observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+    observerService->AddObserver(this, "odoh-service-activated", false);
   }
 
   RefPtr<nsHostResolver> res;
@@ -1242,6 +1243,14 @@ nsDNSService::GetMyHostName(nsACString& result) {
   return NS_ERROR_FAILURE;
 }
 
+NS_IMETHODIMP
+nsDNSService::GetODoHActivated(bool* aResult) {
+  NS_ENSURE_ARG(aResult);
+
+  *aResult = mODoHActivated;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDNSService::Observe(nsISupports* subject, const char* topic,
                       const char16_t* data) {
@@ -1262,6 +1271,8 @@ nsDNSService::Observe(nsISupports* subject, const char* topic,
     }
   } else if (!strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
     Shutdown();
+  } else if (!strcmp(topic, "odoh-service-activated")) {
+    mODoHActivated = u"true"_ns.Equals(data);
   }
 
   if (flushCache && mResolver) {

netwerk/dns/nsDNSService2.h

@@ -103,6 +103,7 @@ class nsDNSService final : public nsPIDNSService,
   uint32_t mResCacheExpiration;
   uint32_t mResCacheGrace;
   bool mResolverPrefsUpdated;
+  bool mODoHActivated = false;
   nsClassHashtable<nsCStringHashKey, nsTArray<nsCString>> mFailedSVCDomainNames;
 };
 

netwerk/dns/nsIDNSService.idl

@@ -243,6 +243,12 @@ interface nsIDNSService : nsISupports
      */
     readonly attribute AUTF8String myHostName;
 
+    /**
+     * Returns true when we have valid ODoHConfigs to encrypt/decrypt oblivious
+     * DNS packets.
+     */
+    readonly attribute boolean ODoHActivated;
+
     /*************************************************************************
      * Listed below are the various flags that may be OR'd together to form
      * the aFlags parameter passed to asyncResolve() and resolve().

netwerk/ipc/PSocketProcess.ipdl

@@ -128,6 +128,7 @@ parent:
                        OriginAttributes aOriginAttributes,
                        nsCString aRequestString)
     returns (bool aAccepted);
+  async ODoHServiceActivated(bool aActivated);
 
 child:
   async Init(SocketPorcessInitAttributes aAttributes);

netwerk/ipc/SocketProcessParent.cpp

@@ -22,6 +22,7 @@
 #include "mozilla/TelemetryIPC.h"
 #include "nsIAppStartup.h"
 #include "nsIHttpActivityObserver.h"
+#include "nsIObserverService.h"
 #include "nsNSSIOLayer.h"
 #include "PSMIPCCommon.h"
 #include "secerr.h"
@@ -425,5 +426,17 @@ SocketProcessParent::RecvPRemoteLazyInputStreamConstructor(
   return IPC_OK();
 }
 
+mozilla::ipc::IPCResult SocketProcessParent::RecvODoHServiceActivated(
+    const bool& aActivated) {
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+
+  if (observerService) {
+    observerService->NotifyObservers(nullptr, "odoh-service-activated",
+                                     aActivated ? u"true" : u"false");
+  }
+  return IPC_OK();
+}
+
 }  // namespace net
 }  // namespace mozilla

netwerk/ipc/SocketProcessParent.h

@@ -119,6 +119,8 @@ class SocketProcessParent final
       PRemoteLazyInputStreamParent* aActor, const nsID& aID,
       const uint64_t& aSize);
 
+  mozilla::ipc::IPCResult RecvODoHServiceActivated(const bool& aActivated);
+
  private:
   SocketProcessHost* mHost;
   UniquePtr<dom::MemoryReportRequestHost> mMemoryReportRequest;

netwerk/protocol/http/nsHttpChannel.cpp

@@ -7312,7 +7312,17 @@ nsHttpChannel::OnStartRequest(nsIRequest* request) {
         NS_SUCCEEDED(mStatus));
   }
 
-  if (gTRRService && gTRRService->IsConfirmed()) {
+  if (StaticPrefs::network_trr_odoh_enabled()) {
+    nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
+    bool ODoHActivated = false;
+    if (dns && NS_SUCCEEDED(dns->GetODoHActivated(&ODoHActivated)) &&
+        ODoHActivated) {
+      Telemetry::Accumulate(Telemetry::HTTP_CHANNEL_ONSTART_SUCCESS_ODOH,
+                            NS_SUCCEEDED(mStatus));
+    }
+  } else if (gTRRService && gTRRService->IsConfirmed()) {
+    // Note this telemetry probe is not working when DNS resolution is done in
+    // the socket process.
     Telemetry::Accumulate(Telemetry::HTTP_CHANNEL_ONSTART_SUCCESS_TRR,
                           TRRService::AutoDetectedKey(), NS_SUCCEEDED(mStatus));
   }

netwerk/test/unit/test_odoh.js

@@ -171,6 +171,7 @@ add_task(async function testODoHQueryA() {
   inRecord.QueryInterface(Ci.nsIDNSAddrRecord);
   let answer = inRecord.getNextAddrAsString();
   Assert.equal(answer, expectedIP);
+  Assert.ok(dns.ODoHActivated);
 });
 
 add_task(async function testODoHQueryAAAA() {
@@ -199,4 +200,5 @@ add_task(async function testODoHQueryAAAA() {
   inRecord.QueryInterface(Ci.nsIDNSAddrRecord);
   let answer = inRecord.getNextAddrAsString();
   Assert.equal(answer, expectedIP);
+  Assert.ok(dns.ODoHActivated);
 });

toolkit/components/telemetry/Histograms.json

@@ -3159,6 +3159,15 @@
     "bug_numbers": [1682552],
     "alert_emails": ["necko@mozilla.com", "kershaw@mozilla.com"]
   },
+  "HTTP_CHANNEL_ONSTART_SUCCESS_ODOH" : {
+    "record_in_processes": ["main"],
+    "products": ["firefox"],
+    "expires_in_version": "never",
+    "kind": "boolean",
+    "description": "Successfully started HTTP channels when ODoH is enabled",
+    "bug_numbers": [1689987],
+    "alert_emails": ["necko@mozilla.com", "kershaw@mozilla.com"]
+  },
   "HTTP_CONNECTION_ENTRY_CACHE_HIT_1" : {
     "record_in_processes": ["main", "content"],
     "products": ["firefox", "fennec"],