chrome/app/client_util.cc

   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 <windows.h>
   6 #include <shlwapi.h>
   7
   8 #include "base/command_line.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/debug/trace_event.h"
  11 #include "base/environment.h"
  12 #include "base/file_version_info.h"
  13 #include "base/lazy_instance.h"
  14 #include "base/logging.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/rand_util.h"  // For PreRead experiment.
  17 #include "base/sha1.h"  // For PreRead experiment.
  18 #include "base/strings/string16.h"
  19 #include "base/strings/string_util.h"
  20 #include "base/strings/stringprintf.h"
  21 #include "base/strings/utf_string_conversions.h"
  22 #include "base/version.h"
  23 #include "base/win/windows_version.h"
  24 #include "chrome/app/chrome_breakpad_client.h"
  25 #include "chrome/app/client_util.h"
  26 #include "chrome/app/image_pre_reader_win.h"
  27 #include "chrome/common/chrome_constants.h"
  28 #include "chrome/common/chrome_result_codes.h"
  29 #include "chrome/common/chrome_switches.h"
  30 #include "chrome/common/env_vars.h"
  31 #include "chrome/installer/util/google_update_constants.h"
  32 #include "chrome/installer/util/google_update_settings.h"
  33 #include "chrome/installer/util/install_util.h"
  34 #include "chrome/installer/util/util_constants.h"
  35 #include "components/breakpad/app/breakpad_client.h"
  36 #include "components/breakpad/app/breakpad_win.h"
  37 #include "content/public/app/startup_helper_win.h"
  38 #include "sandbox/win/src/sandbox.h"
  39
  40 namespace {
  41 // The entry point signature of chrome.dll.
  42 typedef int (*DLL_MAIN)(HINSTANCE, sandbox::SandboxInterfaceInfo*);
  43
  44 typedef void (*RelaunchChromeBrowserWithNewCommandLineIfNeededFunc)();
  45
  46 base::LazyInstance<chrome::ChromeBreakpadClient>::Leaky
  47     g_chrome_breakpad_client = LAZY_INSTANCE_INITIALIZER;
  48
  49 // Returns true if the build date for this module precedes the expiry date
  50 // for the pre-read experiment.
  51 bool PreReadExperimentIsActive() {
  52   const int kPreReadExpiryYear = 2014;
  53   const int kPreReadExpiryMonth = 7;
  54   const int kPreReadExpiryDay = 1;
  55   const char kBuildTimeStr[] = __DATE__ " " __TIME__;
  56
  57   // Get the timestamp of the build.
  58   base::Time build_time;
  59   bool result = base::Time::FromString(kBuildTimeStr, &build_time);
  60   DCHECK(result);
  61
  62   // Get the timestamp at which the experiment expires.
  63   base::Time::Exploded exploded = {0};
  64   exploded.year = kPreReadExpiryYear;
  65   exploded.month = kPreReadExpiryMonth;
  66   exploded.day_of_month = kPreReadExpiryDay;
  67   base::Time expiration_time = base::Time::FromLocalExploded(exploded);
  68
  69   // Return true if the build time predates the expiration time..
  70   return build_time < expiration_time;
  71 }
  72
  73 // Get random unit values, i.e., in the range (0, 1), denoting a die-toss for
  74 // being in an experiment population and experimental group thereof.
  75 void GetPreReadPopulationAndGroup(double* population, double* group) {
  76   // By default we use the metrics id for the user as stable pseudo-random
  77   // input to a hash.
  78   std::string metrics_id;
  79   GoogleUpdateSettings::GetMetricsId(&metrics_id);
  80
  81   // If this user has not metrics id, we fall back to a purely random value
  82   // per browser session.
  83   const size_t kLength = 16;
  84   std::string random_value(metrics_id.empty() ? base::RandBytesAsString(kLength)
  85                                               : metrics_id);
  86
  87   // To interpret the value as a random number we hash it and read the first 8
  88   // bytes of the hash as a unit-interval representing a die-toss for being in
  89   // the experiment population and the second 8 bytes as a die-toss for being
  90   // in various experiment groups.
  91   unsigned char sha1_hash[base::kSHA1Length];
  92   base::SHA1HashBytes(
  93       reinterpret_cast<const unsigned char*>(random_value.c_str()),
  94       random_value.size() * sizeof(random_value[0]),
  95       sha1_hash);
  96   COMPILE_ASSERT(2 * sizeof(uint64) < sizeof(sha1_hash), need_more_data);
  97   const uint64* random_bits = reinterpret_cast<uint64*>(&sha1_hash[0]);
  98
  99   // Convert the bits into unit-intervals and return.
 100   *population = base::BitsToOpenEndedUnitInterval(random_bits[0]);
 101   *group = base::BitsToOpenEndedUnitInterval(random_bits[1]);
 102 }
 103
 104 // Gets the amount of pre-read to use as well as the experiment group in which
 105 // the user falls.
 106 size_t InitPreReadPercentage() {
 107   // By default use the old behaviour: read 100%.
 108   const int kDefaultPercentage = 100;
 109   const char kDefaultFormatStr[] = "%d-pct-default";
 110   const char kControlFormatStr[] = "%d-pct-control";
 111   const char kGroupFormatStr[] = "%d-pct";
 112
 113   COMPILE_ASSERT(kDefaultPercentage <= 100, default_percentage_too_large);
 114   COMPILE_ASSERT(kDefaultPercentage % 5 == 0, default_percentage_not_mult_5);
 115
 116   // Roll the dice to determine if this user is in the experiment and if so,
 117   // in which experimental group.
 118   double population = 0.0;
 119   double group = 0.0;
 120   GetPreReadPopulationAndGroup(&population, &group);
 121
 122   // We limit experiment populations to 1% of the Stable and 10% of each of
 123   // the other channels.
 124   const base::string16 channel(GoogleUpdateSettings::GetChromeChannel(
 125       GoogleUpdateSettings::IsSystemInstall()));
 126   double threshold = (channel == installer::kChromeChannelStable) ? 0.01 : 0.10;
 127
 128   // If the experiment has expired use the default pre-read level. Otherwise,
 129   // those not in the experiment population also use the default pre-read level.
 130   size_t value = kDefaultPercentage;
 131   const char* format_str = kDefaultFormatStr;
 132   if (PreReadExperimentIsActive() && (population <= threshold)) {
 133     // We divide the experiment population into groups pre-reading at 5 percent
 134     // increments in the range [0, 100].
 135     value = static_cast<size_t>(group * 21.0) * 5;
 136     DCHECK_LE(value, 100u);
 137     DCHECK_EQ(0u, value % 5);
 138     format_str =
 139         (value == kDefaultPercentage) ? kControlFormatStr : kGroupFormatStr;
 140   }
 141
 142   // Generate the group name corresponding to this percentage value.
 143   std::string group_name;
 144   base::SStringPrintf(&group_name, format_str, value);
 145
 146   // Persist the group name to the environment so that it can be used for
 147   // reporting.
 148   scoped_ptr<base::Environment> env(base::Environment::Create());
 149   env->SetVar(chrome::kPreReadEnvironmentVariable, group_name);
 150
 151   // Return the percentage value to be used.
 152   return value;
 153 }
 154
 155 // Expects that |dir| has a trailing backslash. |dir| is modified so it
 156 // contains the full path that was tried. Caller must check for the return
 157 // value not being null to determine if this path contains a valid dll.
 158 HMODULE LoadModuleWithDirectory(base::string16* dir,
 159                                 const wchar_t* dll_name,
 160                                 bool pre_read) {
 161   ::SetCurrentDirectoryW(dir->c_str());
 162   dir->append(dll_name);
 163
 164   if (pre_read) {
 165 #if !defined(WIN_DISABLE_PREREAD)
 166     // We pre-read the binary to warm the memory caches (fewer hard faults to
 167     // page parts of the binary in).
 168     const size_t kStepSize = 1024 * 1024;
 169     size_t percentage = InitPreReadPercentage();
 170     ImagePreReader::PartialPreReadImage(dir->c_str(), percentage, kStepSize);
 171 #endif
 172   }
 173
 174   return ::LoadLibraryExW(dir->c_str(), NULL,
 175                           LOAD_WITH_ALTERED_SEARCH_PATH);
 176 }
 177
 178 void RecordDidRun(const base::string16& dll_path) {
 179   bool system_level = !InstallUtil::IsPerUserInstall(dll_path.c_str());
 180   GoogleUpdateSettings::UpdateDidRunState(true, system_level);
 181 }
 182
 183 void ClearDidRun(const base::string16& dll_path) {
 184   bool system_level = !InstallUtil::IsPerUserInstall(dll_path.c_str());
 185   GoogleUpdateSettings::UpdateDidRunState(false, system_level);
 186 }
 187
 188 bool InMetroMode() {
 189   return (wcsstr(
 190       ::GetCommandLineW(), L" -ServerName:DefaultBrowserServer") != NULL);
 191 }
 192
 193 typedef int (*InitMetro)();
 194
 195 }  // namespace
 196
 197 base::string16 GetExecutablePath() {
 198   wchar_t path[MAX_PATH];
 199   ::GetModuleFileNameW(NULL, path, MAX_PATH);
 200   if (!::PathRemoveFileSpecW(path))
 201     return base::string16();
 202   base::string16 exe_path(path);
 203   return exe_path.append(1, L'\\');
 204 }
 205
 206 base::string16 GetCurrentModuleVersion() {
 207   scoped_ptr<FileVersionInfo> file_version_info(
 208       FileVersionInfo::CreateFileVersionInfoForCurrentModule());
 209   if (file_version_info.get()) {
 210     base::string16 version_string(file_version_info->file_version());
 211     if (Version(base::UTF16ToASCII(version_string)).IsValid())
 212       return version_string;
 213   }
 214   return base::string16();
 215 }
 216
 217 //=============================================================================
 218
 219 MainDllLoader::MainDllLoader()
 220   : dll_(NULL), metro_mode_(InMetroMode()) {
 221 }
 222
 223 MainDllLoader::~MainDllLoader() {
 224 }
 225
 226 // Loading chrome is an interesting affair. First we try loading from the
 227 // current directory to support run-what-you-compile and other development
 228 // scenarios.
 229 // If that fails then we look at the version resource in the current
 230 // module. This is the expected path for chrome.exe browser instances in an
 231 // installed build.
 232 HMODULE MainDllLoader::Load(base::string16* version,
 233                             base::string16* out_file) {
 234   const base::string16 executable_dir(GetExecutablePath());
 235   *out_file = executable_dir;
 236
 237   const wchar_t* dll_name = metro_mode_ ?
 238       installer::kChromeMetroDll :
 239 #if !defined(CHROME_MULTIPLE_DLL)
 240       installer::kChromeDll;
 241 #else
 242       (process_type_ == "service")  || process_type_.empty() ?
 243           installer::kChromeDll :
 244           installer::kChromeChildDll;
 245 #endif
 246   const bool pre_read = !metro_mode_;
 247   HMODULE dll = LoadModuleWithDirectory(out_file, dll_name, pre_read);
 248   if (!dll) {
 249     base::string16 version_string(GetCurrentModuleVersion());
 250     if (version_string.empty()) {
 251       LOG(ERROR) << "No valid Chrome version found";
 252       return NULL;
 253     }
 254     *out_file = executable_dir;
 255     *version = version_string;
 256     out_file->append(version_string).append(1, L'\\');
 257     dll = LoadModuleWithDirectory(out_file, dll_name, pre_read);
 258     if (!dll) {
 259       PLOG(ERROR) << "Failed to load Chrome DLL from " << *out_file;
 260       return NULL;
 261     }
 262   }
 263
 264   DCHECK(dll);
 265   return dll;
 266 }
 267
 268 // Launching is a matter of loading the right dll, setting the CHROME_VERSION
 269 // environment variable and just calling the entry point. Derived classes can
 270 // add custom code in the OnBeforeLaunch callback.
 271 int MainDllLoader::Launch(HINSTANCE instance) {
 272   const CommandLine& cmd_line = *CommandLine::ForCurrentProcess();
 273   process_type_ = cmd_line.GetSwitchValueASCII(switches::kProcessType);
 274
 275   base::string16 version;
 276   base::string16 file;
 277
 278   if (metro_mode_) {
 279     HMODULE metro_dll = Load(&version, &file);
 280     if (!metro_dll)
 281       return chrome::RESULT_CODE_MISSING_DATA;
 282
 283     InitMetro chrome_metro_main =
 284         reinterpret_cast<InitMetro>(::GetProcAddress(metro_dll, "InitMetro"));
 285     return chrome_metro_main();
 286   }
 287
 288   // Initialize the sandbox services.
 289   sandbox::SandboxInterfaceInfo sandbox_info = {0};
 290   content::InitializeSandboxInfo(&sandbox_info);
 291
 292   breakpad::SetBreakpadClient(g_chrome_breakpad_client.Pointer());
 293   bool exit_now = true;
 294   if (process_type_.empty()) {
 295     if (breakpad::ShowRestartDialogIfCrashed(&exit_now)) {
 296       // We restarted because of a previous crash. Ask user if we should
 297       // Relaunch. Only for the browser process. See crbug.com/132119.
 298       if (exit_now)
 299         return content::RESULT_CODE_NORMAL_EXIT;
 300     }
 301   }
 302   breakpad::InitCrashReporter(process_type_);
 303
 304   dll_ = Load(&version, &file);
 305   if (!dll_)
 306     return chrome::RESULT_CODE_MISSING_DATA;
 307
 308   scoped_ptr<base::Environment> env(base::Environment::Create());
 309   env->SetVar(chrome::kChromeVersionEnvVar, base::WideToUTF8(version));
 310
 311   OnBeforeLaunch(file);
 312   DLL_MAIN chrome_main =
 313       reinterpret_cast<DLL_MAIN>(::GetProcAddress(dll_, "ChromeMain"));
 314   int rc = chrome_main(instance, &sandbox_info);
 315   return OnBeforeExit(rc, file);
 316 }
 317
 318 void MainDllLoader::RelaunchChromeBrowserWithNewCommandLineIfNeeded() {
 319   if (!dll_)
 320     return;
 321
 322   RelaunchChromeBrowserWithNewCommandLineIfNeededFunc relaunch_function =
 323       reinterpret_cast<RelaunchChromeBrowserWithNewCommandLineIfNeededFunc>(
 324           ::GetProcAddress(dll_,
 325                            "RelaunchChromeBrowserWithNewCommandLineIfNeeded"));
 326   if (!relaunch_function) {
 327     LOG(ERROR) << "Could not find exported function "
 328                << "RelaunchChromeBrowserWithNewCommandLineIfNeeded";
 329   } else {
 330     relaunch_function();
 331   }
 332 }
 333
 334 //=============================================================================
 335
 336 class ChromeDllLoader : public MainDllLoader {
 337  protected:
 338   virtual void OnBeforeLaunch(const base::string16& dll_path) {
 339     RecordDidRun(dll_path);
 340   }
 341
 342   virtual int OnBeforeExit(int return_code, const base::string16& dll_path) {
 343     // NORMAL_EXIT_CANCEL is used for experiments when the user cancels
 344     // so we need to reset the did_run signal so omaha does not count
 345     // this run as active usage.
 346     if (chrome::RESULT_CODE_NORMAL_EXIT_CANCEL == return_code) {
 347       ClearDidRun(dll_path);
 348     }
 349     return return_code;
 350   }
 351 };
 352
 353 //=============================================================================
 354
 355 class ChromiumDllLoader : public MainDllLoader {
 356  protected:
 357   virtual void OnBeforeLaunch(const base::string16& dll_path) OVERRIDE {
 358   }
 359   virtual int OnBeforeExit(int return_code,
 360                            const base::string16& dll_path) OVERRIDE {
 361     return return_code;
 362   }
 363 };
 364
 365 MainDllLoader* MakeMainDllLoader() {
 366 #if defined(GOOGLE_CHROME_BUILD)
 367   return new ChromeDllLoader();
 368 #else
 369   return new ChromiumDllLoader();
 370 #endif
 371 }