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
18namespace 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).
42class 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_
81