net/proxy/proxy_config_service_win.h

   1 // Copyright (c) 2011 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 NET_PROXY_PROXY_CONFIG_SERVICE_WIN_H_
   6 #define NET_PROXY_PROXY_CONFIG_SERVICE_WIN_H_
   7
   8 #include <windows.h>
   9 #include <winhttp.h>
  10
  11 #include <vector>
  12
  13 #include "base/compiler_specific.h"
  14 #include "base/gtest_prod_util.h"
  15 #include "base/win/object_watcher.h"
  16 #include "net/proxy/polling_proxy_config_service.h"
  17
  18 namespace net {
  19
  20 // Implementation of ProxyConfigService that retrieves the system proxy
  21 // settings.
  22 //
  23 // It works by calling WinHttpGetIEProxyConfigForCurrentUser() to fetch the
  24 // Internet Explorer proxy settings.
  25 //
  26 // We use two different strategies to notice when the configuration has
  27 // changed:
  28 //
  29 // (1) Watch the internet explorer settings registry keys for changes. When
  30 //     one of the registry keys pertaining to proxy settings has changed, we
  31 //     call WinHttpGetIEProxyConfigForCurrentUser() again to read the
  32 //     configuration's new value.
  33 //
  34 // (2) Do regular polling every 10 seconds during network activity to see if
  35 //     WinHttpGetIEProxyConfigForCurrentUser() returns something different.
  36 //
  37 // Ideally strategy (1) should be sufficient to pick up all of the changes.
  38 // However we still do the regular polling as a precaution in case the
  39 // implementation details of  WinHttpGetIEProxyConfigForCurrentUser() ever
  40 // change, or in case we got it wrong (and are not checking all possible
  41 // registry dependencies).
  42 class NET_EXPORT_PRIVATE ProxyConfigServiceWin
  43     : public PollingProxyConfigService,
  44       public base::win::ObjectWatcher::Delegate {
  45  public:
  46   ProxyConfigServiceWin();
  47   virtual ~ProxyConfigServiceWin();
  48
  49   // Overrides a function from PollingProxyConfigService.
  50   virtual void AddObserver(Observer* observer) OVERRIDE;
  51
  52  private:
  53   FRIEND_TEST_ALL_PREFIXES(ProxyConfigServiceWinTest, SetFromIEConfig);
  54   class KeyEntry;
  55   typedef std::vector<KeyEntry*> KeyEntryList;
  56
  57   // Registers change observers on the registry keys relating to proxy settings.
  58   void StartWatchingRegistryForChanges();
  59
  60   // Creates a new KeyEntry and appends it to |keys_to_watch_|. If the key
  61   // fails to be created, it is not appended to the list and we return false.
  62   bool AddKeyToWatchList(HKEY rootkey, const wchar_t* subkey);
  63
  64   // ObjectWatcher::Delegate methods:
  65   // This is called whenever one of the registry keys we are watching change.
  66   virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
  67
  68   static void GetCurrentProxyConfig(ProxyConfig* config);
  69
  70   // Set |config| using the proxy configuration values of |ie_config|.
  71   static void SetFromIEConfig(
  72       ProxyConfig* config,
  73       const WINHTTP_CURRENT_USER_IE_PROXY_CONFIG& ie_config);
  74
  75   KeyEntryList keys_to_watch_;
  76 };
  77
  78 }  // namespace net
  79
  80 #endif  // NET_PROXY_PROXY_CONFIG_SERVICE_WIN_H_