components/component_updater/configurator_impl.cc

   1 // Copyright 2014 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 "components/component_updater/configurator_impl.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/command_line.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/strings/string_split.h"
  12 #include "base/strings/string_util.h"
  13 #include "base/version.h"
  14 #include "build/build_config.h"
  15 #include "components/component_updater/component_updater_switches.h"
  16 #include "components/component_updater/component_updater_url_constants.h"
  17 #include "components/update_client/configurator.h"
  18 #include "components/version_info/version_info.h"
  19
  20 #if defined(OS_WIN)
  21 #include "base/win/win_util.h"
  22 #endif  // OS_WIN
  23
  24 namespace component_updater {
  25
  26 namespace {
  27 // Default time constants.
  28 const int kDelayOneMinute = 60;
  29 const int kDelayOneHour = kDelayOneMinute * 60;
  30
  31 // Debug values you can pass to --component-updater=value1,value2.
  32 // Speed up component checking.
  33 const char kSwitchFastUpdate[] = "fast-update";
  34
  35 // Add "testrequest=1" attribute to the update check request.
  36 const char kSwitchRequestParam[] = "test-request";
  37
  38 // Disables pings. Pings are the requests sent to the update server that report
  39 // the success or the failure of component install or update attempts.
  40 extern const char kSwitchDisablePings[] = "disable-pings";
  41
  42 // Sets the URL for updates.
  43 const char kSwitchUrlSource[] = "url-source";
  44
  45 // Disables differential updates.
  46 const char kSwitchDisableDeltaUpdates[] = "disable-delta-updates";
  47
  48 #if defined(OS_WIN)
  49 // Disables background downloads.
  50 const char kSwitchDisableBackgroundDownloads[] = "disable-background-downloads";
  51 #endif  // defined(OS_WIN)
  52
  53 // Returns true if and only if |test| is contained in |vec|.
  54 bool HasSwitchValue(const std::vector<std::string>& vec, const char* test) {
  55   if (vec.empty())
  56     return 0;
  57   return (std::find(vec.begin(), vec.end(), test) != vec.end());
  58 }
  59
  60 // Returns true if falling back on an alternate, unsafe, service URL is
  61 // allowed. In the fallback case, the security of the component update relies
  62 // only on the integrity of the CRX payloads, which is self-validating.
  63 // This is allowed only for some of the pre-Windows Vista versions not including
  64 // Windows XP SP3. As a side note, pings could be sent to the alternate URL too.
  65 bool CanUseAltUrlSource() {
  66 #if defined(OS_WIN)
  67   return !base::win::MaybeHasSHA256Support();
  68 #else
  69   return false;
  70 #endif  // OS_WIN
  71 }
  72
  73 // If there is an element of |vec| of the form |test|=.*, returns the right-
  74 // hand side of that assignment. Otherwise, returns an empty string.
  75 // The right-hand side may contain additional '=' characters, allowing for
  76 // further nesting of switch arguments.
  77 std::string GetSwitchArgument(const std::vector<std::string>& vec,
  78                               const char* test) {
  79   if (vec.empty())
  80     return std::string();
  81   for (std::vector<std::string>::const_iterator it = vec.begin();
  82        it != vec.end(); ++it) {
  83     const std::size_t found = it->find("=");
  84     if (found != std::string::npos) {
  85       if (it->substr(0, found) == test) {
  86         return it->substr(found + 1);
  87       }
  88     }
  89   }
  90   return std::string();
  91 }
  92
  93 }  // namespace
  94
  95 ConfiguratorImpl::ConfiguratorImpl(
  96     const base::CommandLine* cmdline,
  97     net::URLRequestContextGetter* url_request_getter)
  98     : url_request_getter_(url_request_getter),
  99       fast_update_(false),
 100       pings_enabled_(false),
 101       deltas_enabled_(false),
 102       background_downloads_enabled_(false),
 103       fallback_to_alt_source_url_enabled_(false) {
 104   // Parse comma-delimited debug flags.
 105   std::vector<std::string> switch_values = base::SplitString(
 106       cmdline->GetSwitchValueASCII(switches::kComponentUpdater), ",",
 107       base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
 108   fast_update_ = HasSwitchValue(switch_values, kSwitchFastUpdate);
 109   pings_enabled_ = !HasSwitchValue(switch_values, kSwitchDisablePings);
 110   deltas_enabled_ = !HasSwitchValue(switch_values, kSwitchDisableDeltaUpdates);
 111
 112 #if defined(OS_WIN)
 113   background_downloads_enabled_ =
 114       !HasSwitchValue(switch_values, kSwitchDisableBackgroundDownloads);
 115 #else
 116   background_downloads_enabled_ = false;
 117 #endif
 118
 119   const std::string switch_url_source =
 120       GetSwitchArgument(switch_values, kSwitchUrlSource);
 121   if (!switch_url_source.empty()) {
 122     url_source_override_ = GURL(switch_url_source);
 123     DCHECK(url_source_override_.is_valid());
 124   }
 125
 126   if (HasSwitchValue(switch_values, kSwitchRequestParam))
 127     extra_info_ += "testrequest=\"1\"";
 128
 129   fallback_to_alt_source_url_enabled_ = CanUseAltUrlSource();
 130 }
 131
 132 ConfiguratorImpl::~ConfiguratorImpl() {}
 133
 134 int ConfiguratorImpl::InitialDelay() const {
 135   return fast_update_ ? 10 : (6 * kDelayOneMinute);
 136 }
 137
 138 int ConfiguratorImpl::NextCheckDelay() const {
 139   return fast_update_ ? 60 : (6 * kDelayOneHour);
 140 }
 141
 142 int ConfiguratorImpl::StepDelay() const {
 143   return fast_update_ ? 1 : 1;
 144 }
 145
 146 int ConfiguratorImpl::OnDemandDelay() const {
 147   return fast_update_ ? 2 : (30 * kDelayOneMinute);
 148 }
 149
 150 int ConfiguratorImpl::UpdateDelay() const {
 151   return fast_update_ ? 10 : (15 * kDelayOneMinute);
 152 }
 153
 154 std::vector<GURL> ConfiguratorImpl::UpdateUrl() const {
 155   std::vector<GURL> urls;
 156   if (url_source_override_.is_valid()) {
 157     urls.push_back(GURL(url_source_override_));
 158   } else {
 159     urls.push_back(GURL(kUpdaterDefaultUrl));
 160     if (fallback_to_alt_source_url_enabled_) {
 161       urls.push_back(GURL(kUpdaterAltUrl));
 162     }
 163   }
 164   return urls;
 165 }
 166
 167 std::vector<GURL> ConfiguratorImpl::PingUrl() const {
 168   return pings_enabled_ ? UpdateUrl() : std::vector<GURL>();
 169 }
 170
 171 base::Version ConfiguratorImpl::GetBrowserVersion() const {
 172   return base::Version(version_info::GetVersionNumber());
 173 }
 174
 175 std::string ConfiguratorImpl::GetOSLongName() const {
 176   return version_info::GetOSType();
 177 }
 178
 179 std::string ConfiguratorImpl::ExtraRequestParams() const {
 180   return extra_info_;
 181 }
 182
 183 net::URLRequestContextGetter* ConfiguratorImpl::RequestContext() const {
 184   return url_request_getter_;
 185 }
 186
 187 bool ConfiguratorImpl::DeltasEnabled() const {
 188   return deltas_enabled_;
 189 }
 190
 191 bool ConfiguratorImpl::UseBackgroundDownloader() const {
 192   return background_downloads_enabled_;
 193 }
 194
 195 }  // namespace component_updater