Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 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 CHROME_FRAME_DLL_REDIRECTOR_H_ |
| 6 | #define CHROME_FRAME_DLL_REDIRECTOR_H_ |
| 7 | |
| 8 | #include <ObjBase.h> |
| 9 | #include <windows.h> |
| 10 | #include <string> |
| 11 | |
| 12 | #include "base/basictypes.h" |
| 13 | #include "base/memory/scoped_ptr.h" |
| 14 | #include "base/memory/singleton.h" |
| 15 | #include "base/shared_memory.h" |
| 16 | |
| 17 | // Forward |
| 18 | namespace ATL { |
| 19 | class CSecurityAttributes; |
| 20 | } |
Torne (Richard Coles) | c2e0dbd | 2013-05-09 18:35:53 +0100 | [diff] [blame^] | 21 | |
| 22 | namespace base { |
Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 23 | class Version; |
Torne (Richard Coles) | c2e0dbd | 2013-05-09 18:35:53 +0100 | [diff] [blame^] | 24 | } |
Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 25 | |
| 26 | // A singleton class that provides a facility to register the version of the |
| 27 | // current module as the only version that should be loaded system-wide. If |
| 28 | // this module is not the first instance loaded in the system, then the version |
| 29 | // that loaded first will be delegated to. This makes a few assumptions: |
| 30 | // 1) That different versions of the module this code is in reside in |
| 31 | // neighbouring versioned directories, e.g. |
| 32 | // C:\foo\bar\1.2.3.4\my_module.dll |
| 33 | // C:\foo\bar\1.2.3.5\my_module.dll |
| 34 | // 2) That the instance of this class will outlive the module that may be |
| 35 | // delegated to. That is to say, that this class only guarantees that the |
| 36 | // module is loaded as long as this instance is active. |
| 37 | // 3) The module this is compiled into is built with version info. |
| 38 | class DllRedirector { |
| 39 | public: |
| 40 | // Returns the singleton instance. |
| 41 | static DllRedirector* GetInstance(); |
| 42 | |
| 43 | virtual ~DllRedirector(); |
| 44 | |
| 45 | // Attempts to register this Chrome Frame version as the first loaded version |
| 46 | // on the system. If this succeeds, return true. If it fails, it returns |
| 47 | // false meaning that there is another version already loaded somewhere and |
| 48 | // the caller should delegate to that version instead. |
| 49 | bool DllRedirector::RegisterAsFirstCFModule(); |
| 50 | |
| 51 | // Unregisters the well known window class if we registered it earlier. |
| 52 | // This is intended to be called from DllMain under PROCESS_DETACH. |
| 53 | void DllRedirector::UnregisterAsFirstCFModule(); |
| 54 | |
| 55 | // Helper function to return the DllGetClassObject function pointer from |
| 56 | // the given module. This function will return NULL unless |
| 57 | // RegisterAsFirstCFModule has been called first and returned false |
| 58 | // indicating that another module was first in. |
| 59 | // |
| 60 | // On success, the return value is non-null and the first-in module will have |
| 61 | // had its reference count incremented. |
| 62 | LPFNGETCLASSOBJECT GetDllGetClassObjectPtr(); |
| 63 | |
| 64 | protected: |
| 65 | DllRedirector(); |
| 66 | friend struct DefaultSingletonTraits<DllRedirector>; |
| 67 | |
| 68 | // Constructor used for tests. |
| 69 | explicit DllRedirector(const char* shared_memory_name); |
| 70 | |
| 71 | // Returns an HMODULE to the version of the module that should be loaded. |
| 72 | virtual HMODULE GetFirstModule(); |
| 73 | |
| 74 | // Returns the version of the current module or NULL if none can be found. |
Torne (Richard Coles) | c2e0dbd | 2013-05-09 18:35:53 +0100 | [diff] [blame^] | 75 | // The caller must free the returned version. |
| 76 | virtual base::Version* GetCurrentModuleVersion(); |
Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 77 | |
| 78 | // Attempt to load the specified version dll. Finds it by walking up one |
| 79 | // directory from our current module's location, then appending the newly |
| 80 | // found version number. The Version class in base will have ensured that we |
| 81 | // actually have a valid version and not e.g. ..\..\..\..\MyEvilFolder\. |
Torne (Richard Coles) | c2e0dbd | 2013-05-09 18:35:53 +0100 | [diff] [blame^] | 82 | virtual HMODULE LoadVersionedModule(base::Version* version); |
Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 83 | |
| 84 | // Builds the necessary SECURITY_ATTRIBUTES to allow low integrity access |
| 85 | // to an object. Returns true on success, false otherwise. |
| 86 | virtual bool BuildSecurityAttributesForLock( |
| 87 | ATL::CSecurityAttributes* sec_attr); |
| 88 | |
| 89 | // Attempts to change the permissions on the given file mapping to read only. |
| 90 | // Returns true on success, false otherwise. |
| 91 | virtual bool SetFileMappingToReadOnly(base::SharedMemoryHandle mapping); |
| 92 | |
| 93 | // Shared memory segment that contains the version beacon. |
| 94 | scoped_ptr<base::SharedMemory> shared_memory_; |
| 95 | |
| 96 | // The current version of the DLL to be loaded. |
Torne (Richard Coles) | c2e0dbd | 2013-05-09 18:35:53 +0100 | [diff] [blame^] | 97 | scoped_ptr<base::Version> dll_version_; |
Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 98 | |
| 99 | // The handle to the first version of this module that was loaded. This |
| 100 | // may refer to the current module, or another version of the same module |
| 101 | // that we go and load. |
| 102 | HMODULE first_module_handle_; |
| 103 | |
| 104 | // Used for tests to override the name of the shared memory segment. |
| 105 | std::string shared_memory_name_; |
| 106 | |
| 107 | friend class ModuleUtilsTest; |
| 108 | |
| 109 | DISALLOW_COPY_AND_ASSIGN(DllRedirector); |
| 110 | }; |
| 111 | |
| 112 | #endif // CHROME_FRAME_DLL_REDIRECTOR_H_ |