[Windows][Host][Logging] Control event tracing via the registry

This CL adds a some logic to read registry key values to control
the logging state for the host.  I've also integrated the
EventTraceData class with the EtwTraceConsumer for parsing.

The WXS file creates the logging reg key but by default we don't
log anything.  If logging is enabled, then we will create the
ETW classes to control and consume the events.  Once we have
ensured that the functionality is stable and have worked out any
issues, we can consider whether to turn it on by default.

The next CL will add the file logging and event logging classes.
I'd like to land this first to keep the CLs small and get as much
in before branch point as possible.

Bug: 1144185
Change-Id: I5778e57651b6afc99819140c911c2ace79803d74
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2535011Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Commit-Queue: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826926}

remoting/host/daemon_process_win.cc

@@ -60,6 +60,15 @@ IPC::PlatformFileForTransit GetRegistryKeyForTransit(
   return IPC::GetPlatformFileForTransit(handle, false);
 }
 
+#if defined(OFFICIAL_BUILD)
+constexpr wchar_t kLoggingRegistryKeyName[] =
+    L"SOFTWARE\\Google\\Chrome Remote Desktop\\logging";
+#else
+constexpr wchar_t kLoggingRegistryKeyName[] = L"SOFTWARE\\Chromoting\\logging";
+#endif
+
+constexpr wchar_t kLoggingEnabledRegistryValue[] = L"EnableEventLogging";
+
 }  // namespace
 
 namespace remoting {
@@ -245,8 +254,7 @@ std::unique_ptr<DaemonProcess> DaemonProcess::Create(
       caller_task_runner, io_task_runner, std::move(stopped_callback));
 
   // Initialize our ETW logger first so we can capture any subsequent events.
-  // TODO(joedow): Re-enable after we can control logging via the registry.
-  // daemon_process->StartEtwLogging();
+  daemon_process->StartEtwLogging();
 
   daemon_process->Initialize();
 
@@ -398,12 +406,37 @@ bool DaemonProcessWin::OpenPairingRegistry() {
 void DaemonProcessWin::StartEtwLogging() {
   DCHECK(!etw_trace_consumer_);
 
-  // TODO(joedow): Add some registry keys to control the behavior here.
-  // This will most likely include trace levels and output files/locations.
+  base::win::RegKey logging_reg_key;
+  LONG result = logging_reg_key.Open(HKEY_LOCAL_MACHINE,
+                                     kLoggingRegistryKeyName, KEY_READ);
+  if (result != ERROR_SUCCESS) {
+    ::SetLastError(result);
+    PLOG(ERROR) << "Failed to open HKLM\\" << kLoggingRegistryKeyName;
+    return;
+  }
+
+  if (!logging_reg_key.HasValue(kLoggingEnabledRegistryValue)) {
+    VLOG(1) << "Event logging registry value does not exist. EtwTraceConsumer "
+            << "not created.";
+    return;
+  }
+
+  DWORD enabled = 0;
+  result = logging_reg_key.ReadValueDW(kLoggingEnabledRegistryValue, &enabled);
+  if (result != ERROR_SUCCESS) {
+    ::SetLastError(result);
+    PLOG(ERROR) << "Failed to read HKLM\\" << kLoggingRegistryKeyName << "\\"
+                << kLoggingEnabledRegistryValue;
+    return;
+  }
+
+  if (!enabled) {
+    VLOG(1) << "Event logging is not enabled.  EtwTraceConsumer not created.";
+    return;
+  }
+
   etw_trace_consumer_ = EtwTraceConsumer::Create(AutoThread::CreateWithType(
       kEtwTracingThreadName, caller_task_runner(), base::MessagePumpType::IO));
-
-  LOG_IF(ERROR, !etw_trace_consumer_) << "Failed to create EtwTraceConsumer.";
 }
 
 }  // namespace remoting

remoting/host/installer/win/chromoting.wxs

@@ -503,7 +503,7 @@
             <!-- Gives full access to SYSTEM only. -->
             <!-- Cannot use the builtin PermissionEx element because it maps
                  to the MsiLockPermissionsEx table which is not supported on
-                 Windows Installer version 4.5 or lower. Also Cannot use
+                 Windows Installer version 4.5 or lower. Also cannot use
                  PermissionEx in WixUtilExtension because it automatically
                  inherits all the ACLs from the parent. -->
             <Permission User="[WIX_ACCOUNT_LOCALSYSTEM]"
@@ -613,6 +613,15 @@
         <CreateFolder/>
       </Component>
 
+      <Component Id="remoting_logging_registry"
+                 Guid="b640a025-18dd-49b9-b26d-b31252a12f8a">
+        <RegistryKey Root="HKLM"
+                     Key="SOFTWARE\$(var.ChromotingKeyPath)\logging"
+                     Action="create">
+        </RegistryKey>
+        <CreateFolder/>
+      </Component>
+
       <!-- Delete the usagestats flag to reset the crash dump reporting settings
            for existing users. -->
       <Component Id="delete_usagestats"
@@ -731,6 +740,7 @@
       <ComponentRef Id="remoting_desktop"/>
       <ComponentRef Id="remoting_host"/>
       <ComponentRef Id="remoting_lib"/>
+      <ComponentRef Id="remoting_logging_registry"/>
       <ComponentRef Id="remoting_pairing_registry"/>
       <ComponentRef Id="remoting_start_host"/>
       <ComponentRef Id="sawbuck_provider"/>

remoting/host/win/etw_trace_consumer.cc

@@ -17,6 +17,7 @@
 #include "remoting/base/auto_thread_task_runner.h"
 #include "remoting/host/logging.h"
 #include "remoting/host/win/etw_trace_controller.h"
+#include "remoting/host/win/event_trace_data.h"
 
 namespace remoting {
 
@@ -40,7 +41,7 @@ class EtwTraceConsumerImpl : public EtwTraceConsumer {
     Core& operator=(const Core&) = delete;
     ~Core();
 
-    static VOID WINAPI ProcessEvent(PEVENT_TRACE event);
+    static VOID WINAPI ProcessEvent(EVENT_TRACE* event);
 
     bool Start();
     void Stop();
@@ -52,11 +53,11 @@ class EtwTraceConsumerImpl : public EtwTraceConsumer {
 
    private:
     // Parses an event and passes it along to the delegate for processing.
-    void DispatchEvent(PEVENT_TRACE event);
+    void DispatchEvent(EVENT_TRACE* event);
 
     // Handlers which parse and log an ETW event.
-    void HandleFullMessage(PEVENT_TRACE event);
-    void HandleMessage(PEVENT_TRACE event);
+    void HandleFullMessage(const EventTraceData& data);
+    void HandleMessage(const EventTraceData& data);
 
     static Core* instance_;
 
@@ -74,7 +75,7 @@ class EtwTraceConsumerImpl : public EtwTraceConsumer {
 EtwTraceConsumerImpl::Core* EtwTraceConsumerImpl::Core::instance_ = nullptr;
 
 // static
-void EtwTraceConsumerImpl::Core::ProcessEvent(PEVENT_TRACE event) {
+void EtwTraceConsumerImpl::Core::ProcessEvent(EVENT_TRACE* event) {
   // This method is called on the same thread as Consume().
   EtwTraceConsumerImpl::Core* instance = instance_;
   if (instance) {
@@ -129,7 +130,7 @@ void EtwTraceConsumerImpl::Core::ConsumeEvents() {
   Consume();
 }
 
-void EtwTraceConsumerImpl::Core::DispatchEvent(PEVENT_TRACE event) {
+void EtwTraceConsumerImpl::Core::DispatchEvent(EVENT_TRACE* event) {
   // This method is called on the same thread as Consume().
   DCHECK_CALLED_ON_VALID_THREAD(consume_thread_checker_);
   if (!event) {
@@ -141,23 +142,21 @@ void EtwTraceConsumerImpl::Core::DispatchEvent(PEVENT_TRACE event) {
     return;
   }
 
-  uint8_t event_type = event->Header.Class.Type;
-  if (event_type == logging::LOG_MESSAGE_FULL) {
-    HandleFullMessage(event);
-  } else if (event_type != logging::LOG_MESSAGE) {
-    HandleMessage(event);
-  } else {
-    NOTREACHED() << "Unknown event type.";
+  EventTraceData data = EventTraceData::Create(event);
+  if (data.event_type == logging::LOG_MESSAGE_FULL) {
+    HandleFullMessage(data);
+  } else if (data.event_type == logging::LOG_MESSAGE) {
+    HandleMessage(data);
   }
 }
 
-void EtwTraceConsumerImpl::Core::HandleFullMessage(PEVENT_TRACE event) {
-  // TODO(joedow): Implement parsing and logging for this event type.
+void EtwTraceConsumerImpl::Core::HandleFullMessage(const EventTraceData& data) {
+  // TODO(joedow): Implement logging for this event type.
   NOTIMPLEMENTED();
 }
 
-void EtwTraceConsumerImpl::Core::HandleMessage(PEVENT_TRACE event) {
-  // TODO(joedow): Implement parsing and logging for this event type.
+void EtwTraceConsumerImpl::Core::HandleMessage(const EventTraceData& data) {
+  // TODO(joedow): Implement logging for this event type.
   NOTIMPLEMENTED();
 }
 
@@ -208,6 +207,7 @@ std::unique_ptr<EtwTraceConsumer> EtwTraceConsumer::Create(
 
   auto etw_trace_consumer = std::make_unique<EtwTraceConsumerImpl>();
   if (!etw_trace_consumer->StartLogging(task_runner)) {
+    LOG(ERROR) << "Failed to start EtwTraceConsumer instance.";
     return nullptr;
   }