safe_browsing_resource_throttle.h revision 58537e28ecd584eab876aee8be7156509866d23a 
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#ifndef CHROME_BROWSER_RENDERER_HOST_SAFE_BROWSING_RESOURCE_THROTTLE_H_
6#define CHROME_BROWSER_RENDERER_HOST_SAFE_BROWSING_RESOURCE_THROTTLE_H_
7
8#include <string>
9#include <vector>
10
11#include "base/memory/ref_counted.h"
12#include "base/time/time.h"
13#include "base/timer/timer.h"
14#include "chrome/browser/safe_browsing/database_manager.h"
15#include "chrome/browser/safe_browsing/ui_manager.h"
16#include "content/public/browser/resource_throttle.h"
17
18class ResourceDispatcherHost;
19
20namespace net {
21class URLRequest;
22}
23
24// SafeBrowsingResourceThrottle checks that URLs are "safe" before navigating
25// to them. To be considered "safe", a URL must not appear in the
26// malware/phishing blacklists (see SafeBrowsingService for details).
27//
28// This check is done before requesting the original URL, and additionally
29// before following any subsequent redirect.
30//
31// In the common case, the check completes synchronously (no match in the bloom
32// filter), so the request's flow is un-interrupted.
33//
34// However if the URL fails this quick check, it has the possibility of being
35// on the blacklist. Now the request is suspended (prevented from starting),
36// and a more expensive safe browsing check is begun (fetches the full hashes).
37//
38// Note that the safe browsing check takes at most kCheckUrlTimeoutMs
39// milliseconds. If it takes longer than this, then the system defaults to
40// treating the URL as safe.
41//
42// Once the safe browsing check has completed, if the URL was decided to be
43// dangerous, a warning page is thrown up and the request remains suspended.
44// If on the other hand the URL was decided to be safe, the request is
45// resumed.
46class SafeBrowsingResourceThrottle
47    : public content::ResourceThrottle,
48      public SafeBrowsingDatabaseManager::Client,
49      public base::SupportsWeakPtr<SafeBrowsingResourceThrottle> {
50 public:
51  SafeBrowsingResourceThrottle(const net::URLRequest* request,
52                               bool is_subresource,
53                               SafeBrowsingService* safe_browsing);
54
55  // content::ResourceThrottle implementation (called on IO thread):
56  virtual void WillStartRequest(bool* defer) OVERRIDE;
57  virtual void WillRedirectRequest(const GURL& new_url, bool* defer) OVERRIDE;
58
59  // SafeBrowsingDabaseManager::Client implementation (called on IO thread):
60  virtual void OnCheckBrowseUrlResult(
61      const GURL& url, SBThreatType result) OVERRIDE;
62
63 private:
64  // Describes what phase of the check a throttle is in.
65  enum State {
66    STATE_NONE,
67    STATE_CHECKING_URL,
68    STATE_DISPLAYING_BLOCKING_PAGE,
69  };
70
71  // Describes what stage of the request got paused by the check.
72  enum DeferState {
73    DEFERRED_NONE,
74    DEFERRED_START,
75    DEFERRED_REDIRECT,
76  };
77
78  virtual ~SafeBrowsingResourceThrottle();
79
80  // SafeBrowsingService::UrlCheckCallback implementation.
81  void OnBlockingPageComplete(bool proceed);
82
83  // Starts running |url| through the safe browsing check. Returns true if the
84  // URL is safe to visit. Otherwise returns false and will call
85  // OnBrowseUrlResult() when the check has completed.
86  bool CheckUrl(const GURL& url);
87
88  // Callback for when the safe browsing check (which was initiated by
89  // StartCheckingUrl()) has taken longer than kCheckUrlTimeoutMs.
90  void OnCheckUrlTimeout();
91
92  // Starts displaying the safe browsing interstitial page.
93  void StartDisplayingBlockingPage(const GURL& url, SBThreatType threat_type);
94
95  // Resumes the request, by continuing the deferred action (either starting the
96  // request, or following a redirect).
97  void ResumeRequest();
98
99  State state_;
100  DeferState defer_state_;
101
102  // The result of the most recent safe browsing check. Only valid to read this
103  // when state_ != STATE_CHECKING_URL.
104  SBThreatType threat_type_;
105
106  // The time when the outstanding safe browsing check was started.
107  base::TimeTicks url_check_start_time_;
108
109  // Timer to abort the safe browsing check if it takes too long.
110  base::OneShotTimer<SafeBrowsingResourceThrottle> timer_;
111
112  // The redirect chain for this resource
113  std::vector<GURL> redirect_urls_;
114
115  GURL url_being_checked_;
116
117  scoped_refptr<SafeBrowsingDatabaseManager> database_manager_;
118  scoped_refptr<SafeBrowsingUIManager> ui_manager_;
119  const net::URLRequest* request_;
120  bool is_subresource_;
121
122  DISALLOW_COPY_AND_ASSIGN(SafeBrowsingResourceThrottle);
123};
124
125
126#endif  // CHROME_BROWSER_RENDERER_HOST_SAFE_BROWSING_RESOURCE_THROTTLE_H_
127