chrome/browser/intranet_redirect_detector.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 "chrome/browser/intranet_redirect_detector.h"
   6
   7 #include "base/bind.h"
   8 #include "base/command_line.h"
   9 #include "base/prefs/pref_registry_simple.h"
  10 #include "base/prefs/pref_service.h"
  11 #include "base/rand_util.h"
  12 #include "base/stl_util.h"
  13 #include "base/strings/utf_string_conversions.h"
  14 #include "chrome/browser/browser_process.h"
  15 #include "chrome/common/chrome_switches.h"
  16 #include "chrome/common/pref_names.h"
  17 #include "net/base/load_flags.h"
  18 #include "net/base/net_errors.h"
  19 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
  20 #include "net/url_request/url_fetcher.h"
  21 #include "net/url_request/url_request_context_getter.h"
  22 #include "net/url_request/url_request_status.h"
  23
  24 const size_t IntranetRedirectDetector::kNumCharsInHostnames = 10;
  25
  26 IntranetRedirectDetector::IntranetRedirectDetector()
  27     : redirect_origin_(g_browser_process->local_state()->GetString(
  28           prefs::kLastKnownIntranetRedirectOrigin)),
  29       in_sleep_(true),
  30       weak_ptr_factory_(this) {
  31   // Because this function can be called during startup, when kicking off a URL
  32   // fetch can eat up 20 ms of time, we delay seven seconds, which is hopefully
  33   // long enough to be after startup, but still get results back quickly.
  34   // Ideally, instead of this timer, we'd do something like "check if the
  35   // browser is starting up, and if so, come back later", but there is currently
  36   // no function to do this.
  37   static const int kStartFetchDelaySeconds = 7;
  38   base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
  39       base::Bind(&IntranetRedirectDetector::FinishSleep,
  40                  weak_ptr_factory_.GetWeakPtr()),
  41       base::TimeDelta::FromSeconds(kStartFetchDelaySeconds));
  42
  43   net::NetworkChangeNotifier::AddIPAddressObserver(this);
  44 }
  45
  46 IntranetRedirectDetector::~IntranetRedirectDetector() {
  47   net::NetworkChangeNotifier::RemoveIPAddressObserver(this);
  48   STLDeleteElements(&fetchers_);
  49 }
  50
  51 // static
  52 GURL IntranetRedirectDetector::RedirectOrigin() {
  53   const IntranetRedirectDetector* const detector =
  54       g_browser_process->intranet_redirect_detector();
  55   return detector ? detector->redirect_origin_ : GURL();
  56 }
  57
  58 // static
  59 void IntranetRedirectDetector::RegisterPrefs(PrefRegistrySimple* registry) {
  60   registry->RegisterStringPref(prefs::kLastKnownIntranetRedirectOrigin,
  61                                std::string());
  62 }
  63
  64 void IntranetRedirectDetector::FinishSleep() {
  65   in_sleep_ = false;
  66
  67   // If another fetch operation is still running, cancel it.
  68   STLDeleteElements(&fetchers_);
  69   resulting_origins_.clear();
  70
  71   const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
  72   if (cmd_line->HasSwitch(switches::kDisableBackgroundNetworking))
  73     return;
  74
  75   DCHECK(fetchers_.empty() && resulting_origins_.empty());
  76
  77   // Start three fetchers on random hostnames.
  78   for (size_t i = 0; i < 3; ++i) {
  79     std::string url_string("http://");
  80     for (size_t j = 0; j < kNumCharsInHostnames; ++j)
  81       url_string += ('a' + base::RandInt(0, 'z' - 'a'));
  82     GURL random_url(url_string + '/');
  83     net::URLFetcher* fetcher = net::URLFetcher::Create(
  84         random_url, net::URLFetcher::HEAD, this);
  85     // We don't want these fetches to affect existing state in the profile.
  86     fetcher->SetLoadFlags(net::LOAD_DISABLE_CACHE |
  87                           net::LOAD_DO_NOT_SAVE_COOKIES |
  88                           net::LOAD_DO_NOT_SEND_COOKIES);
  89     fetcher->SetRequestContext(g_browser_process->system_request_context());
  90     fetcher->Start();
  91     fetchers_.insert(fetcher);
  92   }
  93 }
  94
  95 void IntranetRedirectDetector::OnURLFetchComplete(
  96     const net::URLFetcher* source) {
  97   // Delete the fetcher on this function's exit.
  98   Fetchers::iterator fetcher = fetchers_.find(
  99       const_cast<net::URLFetcher*>(source));
 100   DCHECK(fetcher != fetchers_.end());
 101   scoped_ptr<net::URLFetcher> clean_up_fetcher(*fetcher);
 102   fetchers_.erase(fetcher);
 103
 104   // If any two fetches result in the same domain/host, we set the redirect
 105   // origin to that; otherwise we set it to nothing.
 106   if (!source->GetStatus().is_success() || (source->GetResponseCode() != 200)) {
 107     if ((resulting_origins_.empty()) ||
 108         ((resulting_origins_.size() == 1) &&
 109          resulting_origins_.front().is_valid())) {
 110       resulting_origins_.push_back(GURL());
 111       return;
 112     }
 113     redirect_origin_ = GURL();
 114   } else {
 115     DCHECK(source->GetURL().is_valid());
 116     GURL origin(source->GetURL().GetOrigin());
 117     if (resulting_origins_.empty()) {
 118       resulting_origins_.push_back(origin);
 119       return;
 120     }
 121     if (net::registry_controlled_domains::SameDomainOrHost(
 122         resulting_origins_.front(),
 123         origin,
 124         net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES)) {
 125       redirect_origin_ = origin;
 126       if (!fetchers_.empty()) {
 127         // Cancel remaining fetch, we don't need it.
 128         DCHECK(fetchers_.size() == 1);
 129         delete (*fetchers_.begin());
 130         fetchers_.clear();
 131       }
 132     }
 133     if (resulting_origins_.size() == 1) {
 134       resulting_origins_.push_back(origin);
 135       return;
 136     }
 137     DCHECK(resulting_origins_.size() == 2);
 138     const bool same_domain_or_host =
 139         net::registry_controlled_domains::SameDomainOrHost(
 140             resulting_origins_.back(),
 141             origin,
 142             net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
 143     redirect_origin_ = same_domain_or_host ? origin : GURL();
 144   }
 145
 146   g_browser_process->local_state()->SetString(
 147       prefs::kLastKnownIntranetRedirectOrigin, redirect_origin_.is_valid() ?
 148           redirect_origin_.spec() : std::string());
 149 }
 150
 151 void IntranetRedirectDetector::OnIPAddressChanged() {
 152   // If a request is already scheduled, do not scheduled yet another one.
 153   if (in_sleep_)
 154     return;
 155
 156   // Since presumably many programs open connections after network changes,
 157   // delay this a little bit.
 158   in_sleep_ = true;
 159   static const int kNetworkSwitchDelayMS = 1000;
 160   base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
 161       base::Bind(&IntranetRedirectDetector::FinishSleep,
 162                  weak_ptr_factory_.GetWeakPtr()),
 163       base::TimeDelta::FromMilliseconds(kNetworkSwitchDelayMS));
 164 }
 165
 166 IntranetRedirectHostResolverProc::IntranetRedirectHostResolverProc(
 167     net::HostResolverProc* previous)
 168     : net::HostResolverProc(previous) {
 169 }
 170
 171 int IntranetRedirectHostResolverProc::Resolve(
 172     const std::string& host,
 173     net::AddressFamily address_family,
 174     net::HostResolverFlags host_resolver_flags,
 175     net::AddressList* addrlist,
 176     int* os_error) {
 177   // We'd love to just ask the IntranetRedirectDetector, but we may not be on
 178   // the same thread.  So just use the heuristic that any all-lowercase a-z
 179   // hostname with the right number of characters is likely from the detector
 180   // (and thus should be blocked).
 181   return ((host.length() == IntranetRedirectDetector::kNumCharsInHostnames) &&
 182       (host.find_first_not_of("abcdefghijklmnopqrstuvwxyz") ==
 183           std::string::npos)) ?
 184       net::ERR_NAME_NOT_RESOLVED :
 185       ResolveUsingPrevious(host, address_family, host_resolver_flags, addrlist,
 186                            os_error);
 187 }