diff options
Diffstat (limited to 'qga/vss-win32.c')
| -rw-r--r-- | qga/vss-win32.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/qga/vss-win32.c b/qga/vss-win32.c new file mode 100644 index 0000000000..24c428842b --- /dev/null +++ b/qga/vss-win32.c @@ -0,0 +1,166 @@ +/* + * 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); +} |