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-rw-r--r--qga/vss-win32.c166
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);
+}