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/strings/string_number_conversions.h"
9 #include "net/base/load_flags.h"
10 #include "net/http/http_response_headers.h"
11 #include "net/url_request/url_request_status.h"
12
13 namespace captive_portal {
14
15 const char CaptivePortalDetector::kDefaultURL[] =
16 "http://www.gstatic.com/generate_204";
17
CaptivePortalDetector(const scoped_refptr<net::URLRequestContextGetter> & request_context)18 CaptivePortalDetector::CaptivePortalDetector(
19 const scoped_refptr<net::URLRequestContextGetter>& request_context)
20 : request_context_(request_context) {
21 }
22
~CaptivePortalDetector()23 CaptivePortalDetector::~CaptivePortalDetector() {
24 }
25
DetectCaptivePortal(const GURL & url,const DetectionCallback & detection_callback)26 void CaptivePortalDetector::DetectCaptivePortal(
27 const GURL& url,
28 const DetectionCallback& detection_callback) {
29 DCHECK(CalledOnValidThread());
30 DCHECK(!FetchingURL());
31 DCHECK(detection_callback_.is_null());
32
33 detection_callback_ = detection_callback;
34
35 // The first 0 means this can use a TestURLFetcherFactory in unit tests.
36 url_fetcher_.reset(net::URLFetcher::Create(0,
37 url,
38 net::URLFetcher::GET,
39 this));
40 url_fetcher_->SetAutomaticallyRetryOn5xx(false);
41 url_fetcher_->SetRequestContext(request_context_.get());
42
43 // Can't safely use net::LOAD_DISABLE_CERT_REVOCATION_CHECKING here,
44 // since then the connection may be reused without checking the cert.
45 url_fetcher_->SetLoadFlags(
46 net::LOAD_BYPASS_CACHE |
47 net::LOAD_DO_NOT_PROMPT_FOR_LOGIN |
48 net::LOAD_DO_NOT_SAVE_COOKIES |
49 net::LOAD_DO_NOT_SEND_COOKIES |
50 net::LOAD_DO_NOT_SEND_AUTH_DATA);
51 url_fetcher_->Start();
52 }
53
Cancel()54 void CaptivePortalDetector::Cancel() {
55 url_fetcher_.reset();
56 detection_callback_.Reset();
57 }
58
OnURLFetchComplete(const net::URLFetcher * source)59 void CaptivePortalDetector::OnURLFetchComplete(const net::URLFetcher* source) {
60 DCHECK(CalledOnValidThread());
61 DCHECK(FetchingURL());
62 DCHECK_EQ(url_fetcher_.get(), source);
63 DCHECK(!detection_callback_.is_null());
64
65 Results results;
66 GetCaptivePortalResultFromResponse(url_fetcher_.get(), &results);
67 DetectionCallback callback = detection_callback_;
68 url_fetcher_.reset();
69 detection_callback_.Reset();
70 callback.Run(results);
71 }
72
73 // Takes a net::URLFetcher that has finished trying to retrieve the test
74 // URL, and returns a CaptivePortalService::Result based on its result.
GetCaptivePortalResultFromResponse(const net::URLFetcher * url_fetcher,Results * results) const75 void CaptivePortalDetector::GetCaptivePortalResultFromResponse(
76 const net::URLFetcher* url_fetcher,
77 Results* results) const {
78 DCHECK(results);
79 DCHECK(!url_fetcher->GetStatus().is_io_pending());
80
81 results->result = captive_portal::RESULT_NO_RESPONSE;
82 results->response_code = url_fetcher->GetResponseCode();
83 results->retry_after_delta = base::TimeDelta();
84 results->landing_url = url_fetcher->GetURL();
85
86 // If there's a network error of some sort when fetching a file via HTTP,
87 // there may be a networking problem, rather than a captive portal.
88 // TODO(mmenke): Consider special handling for redirects that end up at
89 // errors, especially SSL certificate errors.
90 if (url_fetcher->GetStatus().status() != net::URLRequestStatus::SUCCESS)
91 return;
92
93 // In the case of 503 errors, look for the Retry-After header.
94 if (results->response_code == 503) {
95 net::HttpResponseHeaders* headers = url_fetcher->GetResponseHeaders();
96 std::string retry_after_string;
97
98 // If there's no Retry-After header, nothing else to do.
99 if (!headers->EnumerateHeader(NULL, "Retry-After", &retry_after_string))
100 return;
101
102 // Otherwise, try parsing it as an integer (seconds) or as an HTTP date.
103 int seconds;
104 base::Time full_date;
105 if (base::StringToInt(retry_after_string, &seconds)) {
106 results->retry_after_delta = base::TimeDelta::FromSeconds(seconds);
107 } else if (headers->GetTimeValuedHeader("Retry-After", &full_date)) {
108 base::Time now = GetCurrentTime();
109 if (full_date > now)
110 results->retry_after_delta = full_date - now;
111 }
112 return;
113 }
114
115 // A 511 response (Network Authentication Required) means that the user needs
116 // to login to whatever server issued the response.
117 // See: http://tools.ietf.org/html/rfc6585
118 if (results->response_code == 511) {
119 results->result = captive_portal::RESULT_BEHIND_CAPTIVE_PORTAL;
120 return;
121 }
122
123 // Other non-2xx/3xx HTTP responses may indicate server errors.
124 if (results->response_code >= 400 || results->response_code < 200)
125 return;
126
127 // A 204 response code indicates there's no captive portal.
128 if (results->response_code == 204) {
129 results->result = captive_portal::RESULT_INTERNET_CONNECTED;
130 return;
131 }
132
133 // Otherwise, assume it's a captive portal.
134 results->result = captive_portal::RESULT_BEHIND_CAPTIVE_PORTAL;
135 }
136
GetCurrentTime() const137 base::Time CaptivePortalDetector::GetCurrentTime() const {
138 if (time_for_testing_.is_null())
139 return base::Time::Now();
140 else
141 return time_for_testing_;
142 }
143
FetchingURL() const144 bool CaptivePortalDetector::FetchingURL() const {
145 return url_fetcher_.get() != NULL;
146 }
147
148 } // namespace captive_portal
149