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 "net/proxy/polling_proxy_config_service.h"
  16
  17 namespace base {
  18 namespace win {
  19 class RegKey;
  20 }
  21 }  // namespace base.
  22
  23 namespace net {
  24
  25 // Implementation of ProxyConfigService that retrieves the system proxy
  26 // settings.
  27 //
  28 // It works by calling WinHttpGetIEProxyConfigForCurrentUser() to fetch the
  29 // Internet Explorer proxy settings.
  30 //
  31 // We use two different strategies to notice when the configuration has
  32 // changed:
  33 //
  34 // (1) Watch the internet explorer settings registry keys for changes. When
  35 //     one of the registry keys pertaining to proxy settings has changed, we
  36 //     call WinHttpGetIEProxyConfigForCurrentUser() again to read the
  37 //     configuration's new value.
  38 //
  39 // (2) Do regular polling every 10 seconds during network activity to see if
  40 //     WinHttpGetIEProxyConfigForCurrentUser() returns something different.
  41 //
  42 // Ideally strategy (1) should be sufficient to pick up all of the changes.
  43 // However we still do the regular polling as a precaution in case the
  44 // implementation details of  WinHttpGetIEProxyConfigForCurrentUser() ever
  45 // change, or in case we got it wrong (and are not checking all possible
  46 // registry dependencies).
  47 class NET_EXPORT_PRIVATE ProxyConfigServiceWin
  48     : public PollingProxyConfigService {
  49  public:
  50   ProxyConfigServiceWin();
  51   ~ProxyConfigServiceWin() override;
  52
  53   // Overrides a function from PollingProxyConfigService.
  54   void AddObserver(Observer* observer) override;
  55
  56  private:
  57   FRIEND_TEST_ALL_PREFIXES(ProxyConfigServiceWinTest, SetFromIEConfig);
  58   typedef std::vector<base::win::RegKey*> RegKeyList;
  59
  60   // Registers change observers on the registry keys relating to proxy settings.
  61   void StartWatchingRegistryForChanges();
  62
  63   // Creates a new key and appends it to |keys_to_watch_|. If the key fails to
  64   // be created, it is not appended to the list and we return false.
  65   bool AddKeyToWatchList(HKEY rootkey, const wchar_t* subkey);
  66
  67   // This is called whenever one of the registry keys we are watching change.
  68   void OnObjectSignaled(base::win::RegKey* key);
  69
  70   static void GetCurrentProxyConfig(ProxyConfig* config);
  71
  72   // Set |config| using the proxy configuration values of |ie_config|.
  73   static void SetFromIEConfig(
  74       ProxyConfig* config,
  75       const WINHTTP_CURRENT_USER_IE_PROXY_CONFIG& ie_config);
  76
  77   RegKeyList keys_to_watch_;
  78 };
  79
  80 }  // namespace net
  81
  82 #endif  // NET_PROXY_PROXY_CONFIG_SERVICE_WIN_H_