Bug 1866245 - Record telemetry for how many DoH requests we make in private browsing r=necko-reviewers,kershaw

Differential Revision: https://phabricator.services.mozilla.com/D194498

netwerk/dns/TRR.cpp

@@ -43,6 +43,7 @@
 #include "mozilla/UniquePtr.h"
 // Put DNSLogging.h at the end to avoid LOG being overwritten by other headers.
 #include "DNSLogging.h"
+#include "mozilla/glean/GleanMetrics.h"
 
 namespace mozilla {
 namespace net {
@@ -1006,6 +1007,13 @@ TRR::OnStopRequest(nsIRequest* aRequest, nsresult aStatusCode) {
   channel.swap(mChannel);
 
   mChannelStatus = aStatusCode;
+  if (NS_SUCCEEDED(aStatusCode)) {
+    nsCString label = "regular"_ns;
+    if (mPB) {
+      label = "private"_ns;
+    }
+    mozilla::glean::networking::trr_request_count.Get(label).Add(1);
+  }
 
   {
     // Cancel the timer since we don't need it anymore.

netwerk/metrics.yaml

@@ -577,3 +577,19 @@ networking:
     labels:
       - success
       - failure
+
+  trr_request_count:
+    type: labeled_counter
+    description: >
+      The count of successful TRR requests keyed by regular/private browsing
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1866245
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1866245
+    notification_emails:
+      - vgosu@mozilla.com
+      - necko@mozilla.com
+    expires: 130
+    labels:
+      - regular
+      - private

netwerk/test/unit/head_trr.js

@@ -146,7 +146,7 @@ class TRRDNSListener {
         this.additionalInfo,
         this,
         currentThread,
-        {} // defaultOriginAttributes
+        this.options.originAttributes || {} // defaultOriginAttributes
       );
       Assert.ok(!this.options.expectEarlyFail, "asyncResolve ok");
     } catch (e) {

netwerk/test/unit/test_trr.js

@@ -909,3 +909,38 @@ add_task(async function test_padding() {
 });
 
 add_task(test_connection_reuse_and_cycling);
+
+// Can't test for socket process since telemetry is captured in different process.
+add_task(
+  { skip_if: () => mozinfo.socketprocess_networking },
+  async function test_trr_pb_telemetry() {
+    setModeAndURI(Ci.nsIDNSService.MODE_TRRONLY, `doh`);
+    Services.dns.clearCache(true);
+    Services.fog.initializeFOG();
+    Services.fog.testResetFOG();
+    await new TRRDNSListener("testytest.com", { expectedAnswer: "5.5.5.5" });
+
+    Assert.equal(
+      await Glean.networking.trrRequestCount.regular.testGetValue(),
+      2
+    ); // One for IPv4 and one for IPv6.
+    Assert.equal(
+      await Glean.networking.trrRequestCount.private.testGetValue(),
+      null
+    );
+
+    await new TRRDNSListener("testytest.com", {
+      expectedAnswer: "5.5.5.5",
+      originAttributes: { privateBrowsingId: 1 },
+    });
+
+    Assert.equal(
+      await Glean.networking.trrRequestCount.regular.testGetValue(),
+      2
+    );
+    Assert.equal(
+      await Glean.networking.trrRequestCount.private.testGetValue(),
+      2
+    );
+  }
+);