Bug 1675205 - Report telemetry when load an empty file via a JAR archive r=zbraniecki

This will report when a telemetry even whenever we load an empty file via a
JAR channel. It will not catch situations where onStopRequest is called with
an error code, or when the listener of the channel does not consume the stream.

Differential Revision: https://phabricator.services.mozilla.com/D96412

modules/libjar/nsJARChannel.cpp

@@ -19,6 +19,8 @@
 #include "mozilla/BasePrincipal.h"
 #include "mozilla/IntegerPrintfMacros.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/TelemetryComms.h"
 #include "private/pprio.h"
 #include "nsInputStreamPump.h"
 #include "nsThreadUtils.h"
@@ -1023,6 +1025,38 @@ nsJARChannel::OnStartRequest(nsIRequest* req) {
   return rv;
 }
 
+static void RecordEmptyFileEvent(const nsCString& aFileName) {
+  // Send Telemetry
+
+  // The event can only hold 80 characters.
+  // We only save the file name and path inside the jar.
+  auto findFilenameStart = [](const nsCString& aFileName) -> uint32_t {
+    int32_t pos = aFileName.Find("!/");
+    if (pos == kNotFound) {
+      MOZ_ASSERT(false, "This should not happen");
+      return 0;
+    }
+    int32_t from = aFileName.RFindChar('/', pos);
+    if (from == kNotFound) {
+      MOZ_ASSERT(false, "This should not happen");
+      return 0;
+    }
+    // Skip over the slash
+    from++;
+    return from;
+  };
+
+  // If for some reason we are unable to extract the filename we report the
+  // entire string, or 80 characters of it, to make sure we don't miss any
+  // events.
+  uint32_t from = findFilenameStart(aFileName);
+
+  Telemetry::EventID eventType =
+      Telemetry::EventID::NetworkJarChannel_Nodata_Onstop;
+  Telemetry::RecordEvent(eventType, mozilla::Some(Substring(aFileName, from)),
+                         Nothing{});
+}
+
 NS_IMETHODIMP
 nsJARChannel::OnStopRequest(nsIRequest* req, nsresult status) {
   LOG(("nsJARChannel::OnStopRequest [this=%p %s status=%" PRIx32 "]\n", this,
@@ -1031,6 +1065,10 @@ nsJARChannel::OnStopRequest(nsIRequest* req, nsresult status) {
   if (NS_SUCCEEDED(mStatus)) mStatus = status;
 
   if (mListener) {
+    if (NS_SUCCEEDED(status) && !mOnDataCalled) {
+      RecordEmptyFileEvent(mSpec);
+    }
+
     mListener->OnStopRequest(this, status);
     mListener = nullptr;
   }
@@ -1061,6 +1099,7 @@ nsJARChannel::OnDataAvailable(nsIRequest* req, nsIInputStream* stream,
 
   nsresult rv;
 
+  mOnDataCalled = true;
   rv = mListener->OnDataAvailable(this, stream, offset, count);
 
   // simply report progress here instead of hooking ourselves up as a

modules/libjar/nsJARChannel.h

@@ -69,6 +69,7 @@ class nsJARChannel final : public nsIJARChannel,
 
   bool mOpened;
   bool mCanceled;
+  bool mOnDataCalled = false;
 
   RefPtr<nsJARProtocolHandler> mJarHandler;
   nsCOMPtr<nsIJARURI> mJarURI;

modules/libjar/test/unit/test_empty_jar_telemetry.js

@@ -0,0 +1,102 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+"use strict";
+
+const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+const { NetUtil } = ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
+
+const { TelemetryTestUtils } = ChromeUtils.import(
+  "resource://testing-common/TelemetryTestUtils.jsm"
+);
+
+const { TelemetryController } = ChromeUtils.import(
+  "resource://gre/modules/TelemetryController.jsm"
+);
+
+const nsIBinaryInputStream = Components.Constructor(
+  "@mozilla.org/binaryinputstream;1",
+  "nsIBinaryInputStream",
+  "setInputStream"
+);
+
+const fileBase = "test_empty_file.zip";
+const file = do_get_file("data/" + fileBase);
+const jarBase = "jar:" + Services.io.newFileURI(file).spec + "!";
+const tmpDir = Services.dirsvc.get("TmpD", Ci.nsIFile);
+
+function Listener(callback) {
+  this._callback = callback;
+}
+Listener.prototype = {
+  gotStartRequest: false,
+  available: -1,
+  gotStopRequest: false,
+  QueryInterface: ChromeUtils.generateQI(["nsIRequestObserver"]),
+  onDataAvailable(request, stream, offset, count) {
+    try {
+      this.available = stream.available();
+      Assert.equal(this.available, count);
+      // Need to consume stream to avoid assertion
+      new nsIBinaryInputStream(stream).readBytes(count);
+    } catch (ex) {
+      do_throw(ex);
+    }
+  },
+  onStartRequest(request) {
+    this.gotStartRequest = true;
+  },
+  onStopRequest(request, status) {
+    this.gotStopRequest = true;
+    Assert.equal(status, 0);
+    if (this._callback) {
+      this._callback.call(null, this);
+    }
+  },
+};
+
+const TELEMETRY_EVENTS_FILTERS = {
+  category: "network.jar.channel",
+  method: "noData",
+};
+
+add_task(async function test_empty_jar_file() {
+  var copy = tmpDir.clone();
+  copy.append("zzdxphd909dbc6r2bxtqss2m000017");
+  copy.append("zzdxphd909dbc6r2bxtqss2m000017");
+  copy.append(fileBase);
+  file.copyTo(copy.parent, copy.leafName);
+
+  var uri = "jar:" + Services.io.newFileURI(copy).spec + "!/test.txt";
+  var chan = NetUtil.newChannel({ uri, loadUsingSystemPrincipal: true });
+
+  Services.telemetry.setEventRecordingEnabled("network.jar.channel", true);
+  Services.telemetry.clearEvents();
+
+  await new Promise(resolve => {
+    chan.asyncOpen(
+      new Listener(function(l) {
+        Assert.ok(chan.contentLength == 0);
+
+        resolve();
+      })
+    );
+  });
+
+  try {
+    copy.remove(false);
+  } catch (e) {}
+
+  TelemetryTestUtils.assertEvents(
+    [
+      {
+        category: "network.jar.channel",
+        method: "noData",
+        object: "onStop",
+        value: `${fileBase}!/test.txt`,
+      },
+    ],
+    TELEMETRY_EVENTS_FILTERS
+  );
+});

modules/libjar/test/unit/xpcshell.ini

@@ -17,6 +17,7 @@ support-files =
   data/test_crx_dummy.crx
   data/test_umlaute.zip
   data/uncompressed.zip
+  data/test_empty_file.zip
 
 [test_jarchannel.js]
 skip-if = os == "mac"
@@ -44,3 +45,4 @@ skip-if = os == "mac"
 [test_bug1550815.js]
 # recovering from SIGBUS is temporarily disabled by bug 1583735
 skip-if = true
+[test_empty_jar_telemetry.js]

toolkit/components/telemetry/Events.yaml

@@ -2085,6 +2085,27 @@ intl.ui.browserLanguage:
     record_in_processes: ["main"]
     bug_numbers: [1486507, 1553311, 1607501, 1672571]
 
+network.jar.channel:
+  noData:
+    objects: ["onStop"]
+    bug_numbers:
+      - 1675205
+    description: >
+      This event gets recorded whenever onStopRequest gets called with a
+      success code, but no onDataAvailable calls have been made. This indicates
+      an empty file in the JAR archive.
+    notification_emails:
+      - vgosu@mozilla.com
+      - zbraniecki@mozilla.com
+    release_channel_collection: opt-out
+    products:
+      - firefox
+    expiry_version: "93"
+    record_in_processes:
+      - main
+    extra_keys:
+      spec: The path of the file being loaded.
+
 security:
   evalUsage:
     objects: ["systemContext", "parentProcess"]