The Tor Browser: security/sandbox/chromium/base/win/event_trace

     1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.

     2 // Use of this source code is governed by a BSD-style license that can be

     3 // found in the LICENSE file.

     4 //

     5 #include "base/win/event_trace_provider.h"

     6 #include <windows.h>

     7 #include <cguid.h>

     9 namespace base {

    10 namespace win {

    12 TRACE_GUID_REGISTRATION EtwTraceProvider::obligatory_guid_registration_ = {

    13   &GUID_NULL,

    14   NULL

    15 };

    17 EtwTraceProvider::EtwTraceProvider(const GUID& provider_name)

    18     : provider_name_(provider_name), registration_handle_(NULL),

    19       session_handle_(NULL), enable_flags_(0), enable_level_(0) {

    20 }

    22 EtwTraceProvider::EtwTraceProvider()

    23     : provider_name_(GUID_NULL), registration_handle_(NULL),

    24       session_handle_(NULL), enable_flags_(0), enable_level_(0) {

    25 }

    27 EtwTraceProvider::~EtwTraceProvider() {

    28   Unregister();

    29 }

    31 ULONG EtwTraceProvider::EnableEvents(void* buffer) {

    32   session_handle_ = ::GetTraceLoggerHandle(buffer);

    33   if (NULL == session_handle_) {

    34     return ::GetLastError();

    35   }

    37   enable_flags_ = ::GetTraceEnableFlags(session_handle_);

    38   enable_level_ = ::GetTraceEnableLevel(session_handle_);

    40   // Give subclasses a chance to digest the state change.

    41   OnEventsEnabled();

    43   return ERROR_SUCCESS;

    44 }

    46 ULONG EtwTraceProvider::DisableEvents() {

    47   // Give subclasses a chance to digest the state change.

    48   OnEventsDisabled();

    50   enable_level_ = 0;

    51   enable_flags_ = 0;

    52   session_handle_ = NULL;

    54   PostEventsDisabled();

    56   return ERROR_SUCCESS;

    57 }

    59 ULONG EtwTraceProvider::Callback(WMIDPREQUESTCODE request, void* buffer) {

    60   switch (request) {

    61     case WMI_ENABLE_EVENTS:

    62       return EnableEvents(buffer);

    63     case WMI_DISABLE_EVENTS:

    64       return DisableEvents();

    65     default:

    66       return ERROR_INVALID_PARAMETER;

    67   }

    68   // Not reached.

    69 }

    71 ULONG WINAPI EtwTraceProvider::ControlCallback(WMIDPREQUESTCODE request,

    72     void* context, ULONG *reserved, void* buffer) {

    73   EtwTraceProvider *provider = reinterpret_cast<EtwTraceProvider*>(context);

    75   return provider->Callback(request, buffer);

    76 }

    78 ULONG EtwTraceProvider::Register() {

    79   if (provider_name_ == GUID_NULL)

    80     return ERROR_INVALID_NAME;

    82   return ::RegisterTraceGuids(ControlCallback, this, &provider_name_,

    83       1, &obligatory_guid_registration_, NULL, NULL, &registration_handle_);

    84 }

    86 ULONG EtwTraceProvider::Unregister() {

    87   // If a session is active, notify subclasses that it's going away.

    88   if (session_handle_ != NULL)

    89     DisableEvents();

    91   ULONG ret = ::UnregisterTraceGuids(registration_handle_);

    93   registration_handle_ = NULL;

    95   return ret;

    96 }

    98 ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,

    99     EtwEventType type, EtwEventLevel level, const char *message) {

   100   if (NULL == session_handle_ || enable_level_ < level)

   101     return ERROR_SUCCESS;  // No one listening.

   103   EtwMofEvent<1> event(event_class, type, level);

   105   event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);

   106   event.fields[0].Length = message ?

   107       static_cast<ULONG>(sizeof(message[0]) * (1 + strlen(message))) : 0;

   109   return ::TraceEvent(session_handle_, &event.header);

   110 }

   112 ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,

   113     EtwEventType type, EtwEventLevel level, const wchar_t *message) {

   114   if (NULL == session_handle_ || enable_level_ < level)

   115     return ERROR_SUCCESS;  // No one listening.

   117   EtwMofEvent<1> event(event_class, type, level);

   119   event.fields[0].DataPtr = reinterpret_cast<ULONG64>(message);

   120   event.fields[0].Length = message ?

   121       static_cast<ULONG>(sizeof(message[0]) * (1 + wcslen(message))) : 0;

   123   return ::TraceEvent(session_handle_, &event.header);

   124 }

   126 ULONG EtwTraceProvider::Log(EVENT_TRACE_HEADER* event) {

   127   if (enable_level_ < event->Class.Level)

   128     return ERROR_SUCCESS;

   130   return ::TraceEvent(session_handle_, event);

   131 }

   133 }  // namespace win

   134 }  // namespace base

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