components/captive_portal/captive_portal_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 "components/captive_portal/captive_portal_detector.h"
   6
   7 #include "base/logging.h"
   8 #include "base/profiler/scoped_profile.h"
   9 #include "base/strings/string_number_conversions.h"
  10 #include "net/base/load_flags.h"
  11 #include "net/http/http_response_headers.h"
  12 #include "net/url_request/url_request_status.h"
  13
  14 namespace captive_portal {
  15
  16 const char CaptivePortalDetector::kDefaultURL[] =
  17     "http://www.gstatic.com/generate_204";
  18
  19 CaptivePortalDetector::CaptivePortalDetector(
  20     const scoped_refptr<net::URLRequestContextGetter>& request_context)
  21     : request_context_(request_context) {
  22 }
  23
  24 CaptivePortalDetector::~CaptivePortalDetector() {
  25 }
  26
  27 void CaptivePortalDetector::DetectCaptivePortal(
  28     const GURL& url,
  29     const DetectionCallback& detection_callback) {
  30   DCHECK(CalledOnValidThread());
  31   DCHECK(!FetchingURL());
  32   DCHECK(detection_callback_.is_null());
  33
  34   detection_callback_ = detection_callback;
  35
  36   // The first 0 means this can use a TestURLFetcherFactory in unit tests.
  37   url_fetcher_.reset(net::URLFetcher::Create(0,
  38                                              url,
  39                                              net::URLFetcher::GET,
  40                                              this));
  41   url_fetcher_->SetAutomaticallyRetryOn5xx(false);
  42   url_fetcher_->SetRequestContext(request_context_.get());
  43
  44   // Can't safely use net::LOAD_DISABLE_CERT_REVOCATION_CHECKING here,
  45   // since then the connection may be reused without checking the cert.
  46   url_fetcher_->SetLoadFlags(
  47       net::LOAD_BYPASS_CACHE |
  48       net::LOAD_DO_NOT_PROMPT_FOR_LOGIN |
  49       net::LOAD_DO_NOT_SAVE_COOKIES |
  50       net::LOAD_DO_NOT_SEND_COOKIES |
  51       net::LOAD_DO_NOT_SEND_AUTH_DATA);
  52   url_fetcher_->Start();
  53 }
  54
  55 void CaptivePortalDetector::Cancel() {
  56   url_fetcher_.reset();
  57   detection_callback_.Reset();
  58 }
  59
  60 void CaptivePortalDetector::OnURLFetchComplete(const net::URLFetcher* source) {
  61   // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
  62   tracked_objects::ScopedProfile tracking_profile(
  63       FROM_HERE_WITH_EXPLICIT_FUNCTION(
  64           "422577 CaptivePortalDetector::OnURLFetchComplete"));
  65
  66   DCHECK(CalledOnValidThread());
  67   DCHECK(FetchingURL());
  68   DCHECK_EQ(url_fetcher_.get(), source);
  69   DCHECK(!detection_callback_.is_null());
  70
  71   Results results;
  72   GetCaptivePortalResultFromResponse(url_fetcher_.get(), &results);
  73   DetectionCallback callback = detection_callback_;
  74   url_fetcher_.reset();
  75   detection_callback_.Reset();
  76   callback.Run(results);
  77 }
  78
  79 // Takes a net::URLFetcher that has finished trying to retrieve the test
  80 // URL, and returns a CaptivePortalService::Result based on its result.
  81 void CaptivePortalDetector::GetCaptivePortalResultFromResponse(
  82     const net::URLFetcher* url_fetcher,
  83     Results* results) const {
  84   DCHECK(results);
  85   DCHECK(!url_fetcher->GetStatus().is_io_pending());
  86
  87   results->result = captive_portal::RESULT_NO_RESPONSE;
  88   results->response_code = url_fetcher->GetResponseCode();
  89   results->retry_after_delta = base::TimeDelta();
  90   results->landing_url = url_fetcher->GetURL();
  91
  92   // If there's a network error of some sort when fetching a file via HTTP,
  93   // there may be a networking problem, rather than a captive portal.
  94   // TODO(mmenke):  Consider special handling for redirects that end up at
  95   //                errors, especially SSL certificate errors.
  96   if (url_fetcher->GetStatus().status() != net::URLRequestStatus::SUCCESS)
  97     return;
  98
  99   // In the case of 503 errors, look for the Retry-After header.
 100   if (results->response_code == 503) {
 101     net::HttpResponseHeaders* headers = url_fetcher->GetResponseHeaders();
 102     std::string retry_after_string;
 103
 104     // If there's no Retry-After header, nothing else to do.
 105     if (!headers->EnumerateHeader(NULL, "Retry-After", &retry_after_string))
 106       return;
 107
 108     // Otherwise, try parsing it as an integer (seconds) or as an HTTP date.
 109     int seconds;
 110     base::Time full_date;
 111     if (base::StringToInt(retry_after_string, &seconds)) {
 112       results->retry_after_delta = base::TimeDelta::FromSeconds(seconds);
 113     } else if (headers->GetTimeValuedHeader("Retry-After", &full_date)) {
 114       base::Time now = GetCurrentTime();
 115       if (full_date > now)
 116         results->retry_after_delta = full_date - now;
 117     }
 118     return;
 119   }
 120
 121   // A 511 response (Network Authentication Required) means that the user needs
 122   // to login to whatever server issued the response.
 123   // See:  http://tools.ietf.org/html/rfc6585
 124   if (results->response_code == 511) {
 125     results->result = captive_portal::RESULT_BEHIND_CAPTIVE_PORTAL;
 126     return;
 127   }
 128
 129   // Other non-2xx/3xx HTTP responses may indicate server errors.
 130   if (results->response_code >= 400 || results->response_code < 200)
 131     return;
 132
 133   // A 204 response code indicates there's no captive portal.
 134   if (results->response_code == 204) {
 135     results->result = captive_portal::RESULT_INTERNET_CONNECTED;
 136     return;
 137   }
 138
 139   // Otherwise, assume it's a captive portal.
 140   results->result = captive_portal::RESULT_BEHIND_CAPTIVE_PORTAL;
 141 }
 142
 143 base::Time CaptivePortalDetector::GetCurrentTime() const {
 144   if (time_for_testing_.is_null())
 145     return base::Time::Now();
 146   else
 147     return time_for_testing_;
 148 }
 149
 150 bool CaptivePortalDetector::FetchingURL() const {
 151   return url_fetcher_.get() != NULL;
 152 }
 153
 154 }  // namespace captive_portal