| // Copyright 2007-2009 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // ======================================================================== |
| // |
| // Service-related utilities. |
| |
| #ifndef OMAHA_COMMON_SERVICE_UTILS_H__ |
| #define OMAHA_COMMON_SERVICE_UTILS_H__ |
| |
| #include <windows.h> |
| #include <atlstr.h> |
| #include "base/basictypes.h" |
| |
| namespace omaha { |
| |
| // Utility functions for working with the SCM database. |
| class ScmDatabase { |
| public: |
| // Callback function type for EnumerateServices. This gets called for each |
| // service in the registry. |
| // |
| // @param callback_context Passed unchanged from the caller of |
| // EnumerateServices to the callback function. |
| // @param service_name The name of the service (not the display name but |
| // rather the canonical name, to be used with e.g. ::OpenService()). Note |
| // that because this function is based on enumerating the registry, it's |
| // possible that services that were recently deleted will show up in the |
| // enumeration; therefore, it should not be considered an error if you try |
| // to ::OpenService() on this name and it fails with a last error of |
| // ERROR_SERVICE_DOES_NOT_EXIST or possibly ERROR_INVALID_NAME (if |
| // somebody messed up the registry by hand). |
| // |
| // @return S_OK to continue enumeration, S_FALSE or a COM error code to |
| // stop enumeration. The return value will be propagated to the caller |
| // of Enumerate. |
| // |
| // @note The initial version of this function used EnumServicesStatusEx |
| // but it turns out the function is a fair bit flaky, not returning all |
| // recently created (e.g. created but never started) services. |
| typedef HRESULT(*EnumerateServicesCallback)(void* callback_context, |
| const wchar_t* service_name); |
| |
| // Calls 'callback' for each of the services in the registry. |
| // |
| // @param callback Callback function to call |
| // @param callback_context Passed unchanged to your callback function |
| // |
| // @return S_OK or a COM error code. |
| static HRESULT EnumerateServices(EnumerateServicesCallback callback, |
| void* callback_context); |
| |
| // Returns true iff the service passed in is in the indicated state. |
| // |
| // @param service An open handle to a service. The handle must have at |
| // least SERVICE_QUERY_CONFIG rights. |
| // @param state One of the SERVICE_XXX constants indicating the state of a |
| // service (e.g. SERVICE_DISABLED). |
| // |
| // @return True iff 'service' is in state 'state'. |
| static bool IsServiceStateEqual(SC_HANDLE service, DWORD state); |
| |
| // Returns true iff the service passed in has been marked deleted. |
| // |
| // @param service An open handle to a service. The handle must have at |
| // least SERVICE_QUERY_CONFIG and SERVICE_CHANGE_CONFIG rights. |
| // |
| // @return True iff 'service' has been marked deleted. |
| static bool IsServiceMarkedDeleted(SC_HANDLE service); |
| |
| private: |
| DISALLOW_EVIL_CONSTRUCTORS(ScmDatabase); |
| }; |
| |
| // Utility functions for the service's installation, overinstall etc. |
| class ServiceInstall { |
| public: |
| |
| // Generates a versioned service name based on the current system time. |
| static CString GenerateServiceName(const TCHAR* service_prefix); |
| |
| // Uninstalls all versions of the service other than the one that matches |
| // the service name passed in. Pass in NULL to uninstall everything. |
| static HRESULT UninstallServices(const TCHAR* service_prefix, |
| const TCHAR* exclude_service); |
| |
| static bool IsServiceInstalled(const TCHAR* service_name); |
| |
| // @return True if the current service can be installed without rebooting, |
| // false if a reboot is required before it can be installed. The cases |
| // where the current service can be installed without rebooting are: |
| // a) when no service exists with the current name |
| // b) when there is an existing service with the current name but it is |
| // not marked for deletion |
| static bool CanInstallWithoutReboot(); |
| |
| // Given a service name, stops it if it is already running. |
| static HRESULT StopService(const CString& service_name); |
| |
| protected: |
| // Context passed to the UninstallIfNotCurrent function; this is made a |
| // parameter so we can unit test the function without mucking with the |
| // "actual" services. |
| struct UninstallByPrefixParams { |
| CString prefix; // prefix of services we want to uninstall |
| CString unless_matches; // name of current service, to not touch |
| }; |
| |
| // Uninstalls a given service if it matches a given prefix but does not match |
| // a given full service name. |
| // |
| // This is an ScmDatabase::EnumerateServicesCallback function. |
| // |
| // @param context Pointer to an UninstallByPrefix structure. |
| static HRESULT UninstallByPrefix(void* context, const wchar_t* service_name); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceInstall); |
| }; |
| |
| // Service utility functions for querying current state, and eventually more. |
| class ServiceUtils { |
| public: |
| static bool IsServiceRunning(const TCHAR* service_name); |
| static bool IsServiceDisabled(const TCHAR* service_name); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceUtils); |
| }; |
| |
| } // namespace omaha |
| |
| #endif // OMAHA_COMMON_SERVICE_UTILS_H__ |
| |