// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "android_webview/common/crash_reporter/aw_crash_reporter_client.h"

#include <stdint.h>

#include "android_webview/common/aw_channel.h"
#include "android_webview/common/aw_descriptors.h"
#include "android_webview/common/aw_paths.h"
#include "android_webview/common/aw_switches.h"
#include "android_webview/common/crash_reporter/crash_keys.h"
#include "base/android/build_info.h"
#include "base/base_paths_android.h"
#include "base/command_line.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/path_service.h"
#include "base/scoped_native_library.h"
#include "build/build_config.h"
#include "components/crash/content/app/crash_reporter_client.h"
#include "components/crash/content/app/crashpad.h"
#include "components/version_info/version_info.h"
#include "components/version_info/version_info_values.h"

namespace android_webview {
namespace crash_reporter {

namespace {

class AwCrashReporterClient : public ::crash_reporter::CrashReporterClient {
 public:
  AwCrashReporterClient() {}

  // crash_reporter::CrashReporterClient implementation.
  bool IsRunningUnattended() override { return false; }
  bool GetCollectStatsConsent() override {
    // TODO(jperaza): Crashpad uses GetCollectStatsConsent() to enable or
    // disable upload of crash reports. However, Crashpad does not yet support
    // upload on Android, so this return value currently has no effect and
    // WebView's own uploader will determine consent before uploading. If and
    // when Crashpad supports upload on Android, consent can be determined here,
    // or WebView can continue uploading reports itself.
    return false;
  }

  void GetProductNameAndVersion(std::string* product_name,
                                std::string* version,
                                std::string* channel) override {
    *product_name = "AndroidWebView";
    *version = PRODUCT_VERSION;
    *channel =
        version_info::GetChannelString(android_webview::GetChannelOrStable());
  }

  bool GetCrashDumpLocation(base::FilePath* crash_dir) override {
    return base::PathService::Get(android_webview::DIR_CRASH_DUMPS, crash_dir);
  }

  void GetSanitizationInformation(const char* const** annotations_whitelist,
                                  void** target_module,
                                  bool* sanitize_stacks) override {
    *annotations_whitelist = crash_keys::kWebViewCrashKeyWhiteList;
#if defined(COMPONENT_BUILD)
    *target_module = nullptr;
#else
    *target_module = reinterpret_cast<void*>(&EnableCrashReporter);
#endif
    *sanitize_stacks = true;
  }

  unsigned int GetCrashDumpPercentageForWebView() override { return 100; }

  bool GetBrowserProcessType(std::string* ptype) override {
    *ptype = base::CommandLine::ForCurrentProcess()->HasSwitch(
                 switches::kWebViewSandboxedRenderer)
                 ? "browser"
                 : "webview";
    return true;
  }

 private:
  DISALLOW_COPY_AND_ASSIGN(AwCrashReporterClient);
};

base::LazyInstance<AwCrashReporterClient>::Leaky g_crash_reporter_client =
    LAZY_INSTANCE_INITIALIZER;

#if defined(ARCH_CPU_X86_FAMILY)
bool SafeToUseSignalHandler() {
  // N+ shared library namespacing means that we are unable to dlopen
  // libnativebridge (because it isn't in the NDK). However we know
  // that, were we able to, the tests below would pass, so just return
  // true here.
  if (base::android::BuildInfo::GetInstance()->sdk_int() >=
      base::android::SDK_VERSION_NOUGAT) {
    return true;
  }
  // On X86/64 there are binary translators that handle SIGSEGV in userspace and
  // may get chained after our handler - see http://crbug.com/477444
  // We attempt to detect this to work out when it's safe to install breakpad.
  // If anything doesn't seem right we assume it's not safe.

  // type and mangled name of android::NativeBridgeInitialized
  typedef bool (*InitializedFunc)();
  const char kInitializedSymbol[] = "_ZN7android23NativeBridgeInitializedEv";
  // type and mangled name of android::NativeBridgeGetVersion
  typedef uint32_t (*VersionFunc)();
  const char kVersionSymbol[] = "_ZN7android22NativeBridgeGetVersionEv";

  base::ScopedNativeLibrary lib_native_bridge(
      base::FilePath("libnativebridge.so"));
  if (!lib_native_bridge.is_valid()) {
    DLOG(WARNING) << "Couldn't load libnativebridge";
    return false;
  }

  InitializedFunc NativeBridgeInitialized = reinterpret_cast<InitializedFunc>(
      lib_native_bridge.GetFunctionPointer(kInitializedSymbol));
  if (NativeBridgeInitialized == nullptr) {
    DLOG(WARNING) << "Couldn't tell if native bridge initialized";
    return false;
  }
  if (!NativeBridgeInitialized()) {
    // Native process, safe to use breakpad.
    return true;
  }

  VersionFunc NativeBridgeGetVersion = reinterpret_cast<VersionFunc>(
      lib_native_bridge.GetFunctionPointer(kVersionSymbol));
  if (NativeBridgeGetVersion == nullptr) {
    DLOG(WARNING) << "Couldn't get native bridge version";
    return false;
  }
  uint32_t version = NativeBridgeGetVersion();
  if (version >= 2) {
    // Native bridge at least version 2, safe to use breakpad.
    return true;
  } else {
    DLOG(WARNING) << "Native bridge ver=" << version << "; too low";
    return false;
  }
}
#endif

}  // namespace

void EnableCrashReporter(const std::string& process_type) {
  static bool enabled;
  if (enabled) {
    NOTREACHED() << "EnableCrashReporter called more than once";
    return;
  }
  enabled = true;

#if defined(ARCH_CPU_X86_FAMILY)
  if (!SafeToUseSignalHandler()) {
    LOG(WARNING) << "Can't use breakpad to handle WebView crashes";
    return;
  }
#endif

  AwCrashReporterClient* client = g_crash_reporter_client.Pointer();
  ::crash_reporter::SetCrashReporterClient(client);
  ::crash_reporter::InitializeCrashpad(process_type.empty(), process_type);
}

bool GetCrashDumpLocation(base::FilePath* crash_dir) {
  return g_crash_reporter_client.Get().GetCrashDumpLocation(crash_dir);
}

}  // namespace crash_reporter
}  // namespace android_webview