/* * QEMU Guest Agent VSS utility functions * * Copyright Hitachi Data Systems Corp. 2013 * * Authors: * Tomoki Sekiyama <tomoki.sekiyama@hds.com> * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. */ #include <stdio.h> #include <windows.h> #include "qga/guest-agent-core.h" #include "qga/vss-win32.h" #include "qga/vss-win32/requester.h" #define QGA_VSS_DLL "qga-vss.dll" static HMODULE provider_lib; /* Call a function in qga-vss.dll with the specified name */ static HRESULT call_vss_provider_func(const char *func_name) { FARPROC WINAPI func; g_assert(provider_lib); func = GetProcAddress(provider_lib, func_name); if (!func) { char *msg; FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (char *)&msg, 0, NULL); fprintf(stderr, "failed to load %s from %s: %s", func_name, QGA_VSS_DLL, msg); LocalFree(msg); return E_FAIL; } return func(); } /* Check whether this OS version supports VSS providers */ static bool vss_check_os_version(void) { OSVERSIONINFO OSver; OSver.dwOSVersionInfoSize = sizeof(OSVERSIONINFO); GetVersionEx(&OSver); if ((OSver.dwMajorVersion == 5 && OSver.dwMinorVersion >= 2) || OSver.dwMajorVersion > 5) { BOOL wow64 = false; #ifndef _WIN64 /* Provider doesn't work under WOW64 (32bit agent on 64bit OS) */ if (!IsWow64Process(GetCurrentProcess(), &wow64)) { fprintf(stderr, "failed to IsWow64Process (Error: %lx\n)\n", GetLastError()); return false; } if (wow64) { fprintf(stderr, "Warning: Running under WOW64\n"); } #endif return !wow64; } return false; } /* Load qga-vss.dll */ bool vss_init(bool init_requester) { if (!vss_check_os_version()) { /* Do nothing if OS doesn't support providers. */ fprintf(stderr, "VSS provider is not supported in this OS version: " "fsfreeze is disabled.\n"); return false; } provider_lib = LoadLibraryA(QGA_VSS_DLL); if (!provider_lib) { char *msg; FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (char *)&msg, 0, NULL); fprintf(stderr, "failed to load %s: %sfsfreeze is disabled\n", QGA_VSS_DLL, msg); LocalFree(msg); return false; } if (init_requester) { HRESULT hr = call_vss_provider_func("requester_init"); if (FAILED(hr)) { fprintf(stderr, "fsfreeze is disabled.\n"); vss_deinit(false); return false; } } return true; } /* Unload qga-provider.dll */ void vss_deinit(bool deinit_requester) { if (deinit_requester) { call_vss_provider_func("requester_deinit"); } FreeLibrary(provider_lib); provider_lib = NULL; } bool vss_initialized(void) { return !!provider_lib; } int ga_install_vss_provider(void) { HRESULT hr; if (!vss_init(false)) { fprintf(stderr, "Installation of VSS provider is skipped. " "fsfreeze will be disabled.\n"); return 0; } hr = call_vss_provider_func("COMRegister"); vss_deinit(false); return SUCCEEDED(hr) ? 0 : EXIT_FAILURE; } void ga_uninstall_vss_provider(void) { if (!vss_init(false)) { fprintf(stderr, "Removal of VSS provider is skipped.\n"); return; } call_vss_provider_func("COMUnregister"); vss_deinit(false); } /* Call VSS requester and freeze/thaw filesystems and applications */ void qga_vss_fsfreeze(int *nr_volume, Error **err, bool freeze) { const char *func_name = freeze ? "requester_freeze" : "requester_thaw"; QGAVSSRequesterFunc func; ErrorSet errset = { .error_set = (ErrorSetFunc)error_set_win32, .errp = (void **)err, .err_class = ERROR_CLASS_GENERIC_ERROR }; func = (QGAVSSRequesterFunc)GetProcAddress(provider_lib, func_name); if (!func) { error_setg_win32(err, GetLastError(), "failed to load %s from %s", func_name, QGA_VSS_DLL); return; } func(nr_volume, &errset); }