1 files changed, 141 insertions, 0 deletions
diff --git a/qga/vss-win32.c b/qga/vss-win32.c
new file mode 100644
index 0000000000..89c0f3bd18
--- /dev/null
+++ b/qga/vss-win32.c
@@ -0,0 +1,141 @@
+/*
+ * 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;
+}
+
+/* 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);
+}