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      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 #ifndef CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_URL_FILTER_H_
      6 #define CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_URL_FILTER_H_
      7 
      8 #include "base/callback_forward.h"
      9 #include "base/memory/ref_counted.h"
     10 #include "base/memory/scoped_ptr.h"
     11 #include "base/memory/scoped_vector.h"
     12 #include "base/observer_list.h"
     13 #include "base/threading/non_thread_safe.h"
     14 #include "base/values.h"
     15 #include "chrome/browser/supervised_user/supervised_user_site_list.h"
     16 #include "chrome/browser/supervised_user/supervised_users.h"
     17 
     18 class GURL;
     19 
     20 // This class manages the filtering behavior for a given URL, i.e. it tells
     21 // callers if a given URL should be allowed, blocked or warned about. It uses
     22 // information from multiple sources:
     23 //   * A default setting (allow, block or warn).
     24 //   * The set of installed and enabled content packs, which contain whitelists
     25 //     of URL patterns that should be allowed.
     26 //   * User-specified manual overrides (allow or block) for either sites
     27 //     (hostnames) or exact URLs, which take precedence over the previous
     28 //     sources.
     29 // References to it can be passed around on different threads (the refcounting
     30 // is thread-safe), but the object itself should always be accessed on the same
     31 // thread (member access isn't thread-safe).
     32 class SupervisedUserURLFilter
     33     : public base::RefCountedThreadSafe<SupervisedUserURLFilter>,
     34       public base::NonThreadSafe {
     35  public:
     36   enum FilteringBehavior {
     37     ALLOW,
     38     WARN,
     39     BLOCK,
     40     HISTOGRAM_BOUNDING_VALUE
     41   };
     42 
     43   class Observer {
     44    public:
     45     virtual void OnSiteListUpdated() = 0;
     46   };
     47 
     48   struct Contents;
     49 
     50   SupervisedUserURLFilter();
     51 
     52   static FilteringBehavior BehaviorFromInt(int behavior_value);
     53 
     54   // Normalizes a URL for matching purposes.
     55   static GURL Normalize(const GURL& url);
     56 
     57   // Returns true if the URL has a standard scheme. Only URLs with standard
     58   // schemes are filtered.
     59   // This method is public for testing.
     60   static bool HasFilteredScheme(const GURL& url);
     61 
     62   // Returns true if the |host| matches the pattern. A pattern is a hostname
     63   // with one or both of the following modifications:
     64   // - If the pattern starts with "*.", it matches the host or any subdomain
     65   //   (e.g. the pattern "*.google.com" would match google.com, www.google.com,
     66   //   or accounts.google.com).
     67   // - If the pattern ends with ".*", it matches the host on any known TLD
     68   //   (e.g. the pattern "google.*" would match google.com or google.co.uk).
     69   // See the SupervisedUserURLFilterTest.HostMatchesPattern unit test for more
     70   // examples.
     71   // Asterisks in other parts of the pattern are not allowed.
     72   // |host| and |pattern| are assumed to be normalized to lower-case.
     73   // This method is public for testing.
     74   static bool HostMatchesPattern(const std::string& host,
     75                                  const std::string& pattern);
     76 
     77   void GetSites(const GURL& url,
     78                 std::vector<SupervisedUserSiteList::Site*>* sites) const;
     79 
     80   // Returns the filtering behavior for a given URL, based on the default
     81   // behavior and whether it is on a site list.
     82   FilteringBehavior GetFilteringBehaviorForURL(const GURL& url) const;
     83 
     84   // Sets the filtering behavior for pages not on a list (default is ALLOW).
     85   void SetDefaultFilteringBehavior(FilteringBehavior behavior);
     86 
     87   // Asynchronously loads the specified site lists from disk and updates the
     88   // filter to recognize each site on them.
     89   // Calls |continuation| when the filter has been updated.
     90   void LoadWhitelists(ScopedVector<SupervisedUserSiteList> site_lists);
     91 
     92   // Set the list of matched patterns to the passed in list.
     93   // This method is only used for testing.
     94   void SetFromPatterns(const std::vector<std::string>& patterns);
     95 
     96   // Sets the set of manually allowed or blocked hosts.
     97   void SetManualHosts(const std::map<std::string, bool>* host_map);
     98 
     99   // Sets the set of manually allowed or blocked URLs.
    100   void SetManualURLs(const std::map<GURL, bool>* url_map);
    101 
    102   void AddObserver(Observer* observer);
    103   void RemoveObserver(Observer* observer);
    104 
    105  private:
    106   friend class base::RefCountedThreadSafe<SupervisedUserURLFilter>;
    107   ~SupervisedUserURLFilter();
    108 
    109   void SetContents(scoped_ptr<Contents> url_matcher);
    110 
    111   ObserverList<Observer> observers_;
    112 
    113   FilteringBehavior default_behavior_;
    114   scoped_ptr<Contents> contents_;
    115 
    116   // Maps from a URL to whether it is manually allowed (true) or blocked
    117   // (false).
    118   std::map<GURL, bool> url_map_;
    119 
    120   // Maps from a hostname to whether it is manually allowed (true) or blocked
    121   // (false).
    122   std::map<std::string, bool> host_map_;
    123 
    124   DISALLOW_COPY_AND_ASSIGN(SupervisedUserURLFilter);
    125 };
    126 
    127 #endif  // CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_URL_FILTER_H_
    128