xref: /openbmc/qemu/qga/vss-win32/provider.cpp (revision a42e9c41) 
1 /*
2  * QEMU Guest Agent win32 VSS Provider implementations
3  *
4  * Copyright Hitachi Data Systems Corp. 2013
5  *
6  * Authors:
7  *  Tomoki Sekiyama   <tomoki.sekiyama@hds.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 
13 #include <stdio.h>
14 #include "vss-common.h"
15 #include "inc/win2003/vscoordint.h"
16 #include "inc/win2003/vsprov.h"
17 
18 #define VSS_TIMEOUT_MSEC (60*1000)
19 
20 static long g_nComObjsInUse;
21 HINSTANCE g_hinstDll;
22 
23 /* VSS common GUID's */
24 
25 const CLSID CLSID_VSSCoordinator = { 0xE579AB5F, 0x1CC4, 0x44b4,
26     {0xBE, 0xD9, 0xDE, 0x09, 0x91, 0xFF, 0x06, 0x23} };
27 const IID IID_IVssAdmin = { 0x77ED5996, 0x2F63, 0x11d3,
28     {0x8A, 0x39, 0x00, 0xC0, 0x4F, 0x72, 0xD8, 0xE3} };
29 
30 const IID IID_IVssHardwareSnapshotProvider = { 0x9593A157, 0x44E9, 0x4344,
31     {0xBB, 0xEB, 0x44, 0xFB, 0xF9, 0xB0, 0x6B, 0x10} };
32 const IID IID_IVssSoftwareSnapshotProvider = { 0x609e123e, 0x2c5a, 0x44d3,
33     {0x8f, 0x01, 0x0b, 0x1d, 0x9a, 0x47, 0xd1, 0xff} };
34 const IID IID_IVssProviderCreateSnapshotSet = { 0x5F894E5B, 0x1E39, 0x4778,
35     {0x8E, 0x23, 0x9A, 0xBA, 0xD9, 0xF0, 0xE0, 0x8C} };
36 const IID IID_IVssProviderNotifications = { 0xE561901F, 0x03A5, 0x4afe,
37     {0x86, 0xD0, 0x72, 0xBA, 0xEE, 0xCE, 0x70, 0x04} };
38 
39 const IID IID_IVssEnumObject = { 0xAE1C7110, 0x2F60, 0x11d3,
40     {0x8A, 0x39, 0x00, 0xC0, 0x4F, 0x72, 0xD8, 0xE3} };
41 
42 
43 void LockModule(BOOL lock)
44 {
45     if (lock) {
46         InterlockedIncrement(&g_nComObjsInUse);
47     } else {
48         InterlockedDecrement(&g_nComObjsInUse);
49     }
50 }
51 
52 /* Empty enumerator for VssObject */
53 
54 class CQGAVSSEnumObject : public IVssEnumObject
55 {
56 public:
57     STDMETHODIMP QueryInterface(REFIID riid, void **ppObj);
58     STDMETHODIMP_(ULONG) AddRef();
59     STDMETHODIMP_(ULONG) Release();
60 
61     /* IVssEnumObject Methods */
62     STDMETHODIMP Next(
63         ULONG celt, VSS_OBJECT_PROP *rgelt, ULONG *pceltFetched);
64     STDMETHODIMP Skip(ULONG celt);
65     STDMETHODIMP Reset(void);
66     STDMETHODIMP Clone(IVssEnumObject **ppenum);
67 
68     /* CQGAVSSEnumObject Methods */
69     CQGAVSSEnumObject();
70     ~CQGAVSSEnumObject();
71 
72 private:
73     long m_nRefCount;
74 };
75 
76 CQGAVSSEnumObject::CQGAVSSEnumObject()
77 {
78     m_nRefCount = 0;
79     LockModule(TRUE);
80 }
81 
82 CQGAVSSEnumObject::~CQGAVSSEnumObject()
83 {
84     LockModule(FALSE);
85 }
86 
87 STDMETHODIMP CQGAVSSEnumObject::QueryInterface(REFIID riid, void **ppObj)
88 {
89     if (riid == IID_IUnknown || riid == IID_IVssEnumObject) {
90         *ppObj = static_cast<void*>(static_cast<IVssEnumObject*>(this));
91         AddRef();
92         return S_OK;
93     }
94     *ppObj = NULL;
95     return E_NOINTERFACE;
96 }
97 
98 STDMETHODIMP_(ULONG) CQGAVSSEnumObject::AddRef()
99 {
100     return InterlockedIncrement(&m_nRefCount);
101 }
102 
103 STDMETHODIMP_(ULONG) CQGAVSSEnumObject::Release()
104 {
105     long nRefCount = InterlockedDecrement(&m_nRefCount);
106     if (m_nRefCount == 0) {
107         delete this;
108     }
109     return nRefCount;
110 }
111 
112 STDMETHODIMP CQGAVSSEnumObject::Next(
113     ULONG celt, VSS_OBJECT_PROP *rgelt, ULONG *pceltFetched)
114 {
115     *pceltFetched = 0;
116     return S_FALSE;
117 }
118 
119 STDMETHODIMP CQGAVSSEnumObject::Skip(ULONG celt)
120 {
121     return S_FALSE;
122 }
123 
124 STDMETHODIMP CQGAVSSEnumObject::Reset(void)
125 {
126     return S_OK;
127 }
128 
129 STDMETHODIMP CQGAVSSEnumObject::Clone(IVssEnumObject **ppenum)
130 {
131     return E_NOTIMPL;
132 }
133 
134 
135 /* QGAVssProvider */
136 
137 class CQGAVssProvider :
138     public IVssSoftwareSnapshotProvider,
139     public IVssProviderCreateSnapshotSet,
140     public IVssProviderNotifications
141 {
142 public:
143     STDMETHODIMP QueryInterface(REFIID riid, void **ppObj);
144     STDMETHODIMP_(ULONG) AddRef();
145     STDMETHODIMP_(ULONG) Release();
146 
147     /* IVssSoftwareSnapshotProvider Methods */
148     STDMETHODIMP SetContext(LONG lContext);
149     STDMETHODIMP GetSnapshotProperties(
150         VSS_ID SnapshotId, VSS_SNAPSHOT_PROP *pProp);
151     STDMETHODIMP Query(
152         VSS_ID QueriedObjectId, VSS_OBJECT_TYPE eQueriedObjectType,
153         VSS_OBJECT_TYPE eReturnedObjectsType, IVssEnumObject **ppEnum);
154     STDMETHODIMP DeleteSnapshots(
155         VSS_ID SourceObjectId, VSS_OBJECT_TYPE eSourceObjectType,
156         BOOL bForceDelete, LONG *plDeletedSnapshots,
157         VSS_ID *pNondeletedSnapshotID);
158     STDMETHODIMP BeginPrepareSnapshot(
159         VSS_ID SnapshotSetId, VSS_ID SnapshotId,
160         VSS_PWSZ pwszVolumeName, LONG lNewContext);
161     STDMETHODIMP IsVolumeSupported(
162         VSS_PWSZ pwszVolumeName, BOOL *pbSupportedByThisProvider);
163     STDMETHODIMP IsVolumeSnapshotted(
164         VSS_PWSZ pwszVolumeName, BOOL *pbSnapshotsPresent,
165         LONG *plSnapshotCompatibility);
166     STDMETHODIMP SetSnapshotProperty(
167         VSS_ID SnapshotId, VSS_SNAPSHOT_PROPERTY_ID eSnapshotPropertyId,
168         VARIANT vProperty);
169     STDMETHODIMP RevertToSnapshot(VSS_ID SnapshotId);
170     STDMETHODIMP QueryRevertStatus(VSS_PWSZ pwszVolume, IVssAsync **ppAsync);
171 
172     /* IVssProviderCreateSnapshotSet Methods */
173     STDMETHODIMP EndPrepareSnapshots(VSS_ID SnapshotSetId);
174     STDMETHODIMP PreCommitSnapshots(VSS_ID SnapshotSetId);
175     STDMETHODIMP CommitSnapshots(VSS_ID SnapshotSetId);
176     STDMETHODIMP PostCommitSnapshots(
177         VSS_ID SnapshotSetId, LONG lSnapshotsCount);
178     STDMETHODIMP PreFinalCommitSnapshots(VSS_ID SnapshotSetId);
179     STDMETHODIMP PostFinalCommitSnapshots(VSS_ID SnapshotSetId);
180     STDMETHODIMP AbortSnapshots(VSS_ID SnapshotSetId);
181 
182     /* IVssProviderNotifications Methods */
183     STDMETHODIMP OnLoad(IUnknown *pCallback);
184     STDMETHODIMP OnUnload(BOOL bForceUnload);
185 
186     /* CQGAVssProvider Methods */
187     CQGAVssProvider();
188     ~CQGAVssProvider();
189 
190 private:
191     long m_nRefCount;
192 };
193 
194 CQGAVssProvider::CQGAVssProvider()
195 {
196     m_nRefCount = 0;
197     LockModule(TRUE);
198 }
199 
200 CQGAVssProvider::~CQGAVssProvider()
201 {
202     LockModule(FALSE);
203 }
204 
205 STDMETHODIMP CQGAVssProvider::QueryInterface(REFIID riid, void **ppObj)
206 {
207     if (riid == IID_IUnknown) {
208         *ppObj = static_cast<void*>(this);
209         AddRef();
210         return S_OK;
211     }
212     if (riid == IID_IVssSoftwareSnapshotProvider) {
213         *ppObj = static_cast<void*>(
214             static_cast<IVssSoftwareSnapshotProvider*>(this));
215         AddRef();
216         return S_OK;
217     }
218     if (riid == IID_IVssProviderCreateSnapshotSet) {
219         *ppObj = static_cast<void*>(
220             static_cast<IVssProviderCreateSnapshotSet*>(this));
221         AddRef();
222         return S_OK;
223     }
224     if (riid == IID_IVssProviderNotifications) {
225         *ppObj = static_cast<void*>(
226             static_cast<IVssProviderNotifications*>(this));
227         AddRef();
228         return S_OK;
229     }
230     *ppObj = NULL;
231     return E_NOINTERFACE;
232 }
233 
234 STDMETHODIMP_(ULONG) CQGAVssProvider::AddRef()
235 {
236     return InterlockedIncrement(&m_nRefCount);
237 }
238 
239 STDMETHODIMP_(ULONG) CQGAVssProvider::Release()
240 {
241     long nRefCount = InterlockedDecrement(&m_nRefCount);
242     if (m_nRefCount == 0) {
243         delete this;
244     }
245     return nRefCount;
246 }
247 
248 
249 /*
250  * IVssSoftwareSnapshotProvider methods
251  */
252 
253 STDMETHODIMP CQGAVssProvider::SetContext(LONG lContext)
254 {
255     return S_OK;
256 }
257 
258 STDMETHODIMP CQGAVssProvider::GetSnapshotProperties(
259     VSS_ID SnapshotId, VSS_SNAPSHOT_PROP *pProp)
260 {
261     return VSS_E_OBJECT_NOT_FOUND;
262 }
263 
264 STDMETHODIMP CQGAVssProvider::Query(
265     VSS_ID QueriedObjectId, VSS_OBJECT_TYPE eQueriedObjectType,
266     VSS_OBJECT_TYPE eReturnedObjectsType, IVssEnumObject **ppEnum)
267 {
268     try {
269         *ppEnum = new CQGAVSSEnumObject;
270     } catch (...) {
271         return E_OUTOFMEMORY;
272     }
273     (*ppEnum)->AddRef();
274     return S_OK;
275 }
276 
277 STDMETHODIMP CQGAVssProvider::DeleteSnapshots(
278     VSS_ID SourceObjectId, VSS_OBJECT_TYPE eSourceObjectType,
279     BOOL bForceDelete, LONG *plDeletedSnapshots, VSS_ID *pNondeletedSnapshotID)
280 {
281     return E_NOTIMPL;
282 }
283 
284 STDMETHODIMP CQGAVssProvider::BeginPrepareSnapshot(
285     VSS_ID SnapshotSetId, VSS_ID SnapshotId,
286     VSS_PWSZ pwszVolumeName, LONG lNewContext)
287 {
288     return S_OK;
289 }
290 
291 STDMETHODIMP CQGAVssProvider::IsVolumeSupported(
292     VSS_PWSZ pwszVolumeName, BOOL *pbSupportedByThisProvider)
293 {
294     *pbSupportedByThisProvider = TRUE;
295 
296     return S_OK;
297 }
298 
299 STDMETHODIMP CQGAVssProvider::IsVolumeSnapshotted(VSS_PWSZ pwszVolumeName,
300     BOOL *pbSnapshotsPresent, LONG *plSnapshotCompatibility)
301 {
302     *pbSnapshotsPresent = FALSE;
303     *plSnapshotCompatibility = 0;
304     return S_OK;
305 }
306 
307 STDMETHODIMP CQGAVssProvider::SetSnapshotProperty(VSS_ID SnapshotId,
308     VSS_SNAPSHOT_PROPERTY_ID eSnapshotPropertyId, VARIANT vProperty)
309 {
310     return E_NOTIMPL;
311 }
312 
313 STDMETHODIMP CQGAVssProvider::RevertToSnapshot(VSS_ID SnapshotId)
314 {
315     return E_NOTIMPL;
316 }
317 
318 STDMETHODIMP CQGAVssProvider::QueryRevertStatus(
319     VSS_PWSZ pwszVolume, IVssAsync **ppAsync)
320 {
321     return E_NOTIMPL;
322 }
323 
324 
325 /*
326  * IVssProviderCreateSnapshotSet methods
327  */
328 
329 STDMETHODIMP CQGAVssProvider::EndPrepareSnapshots(VSS_ID SnapshotSetId)
330 {
331     return S_OK;
332 }
333 
334 STDMETHODIMP CQGAVssProvider::PreCommitSnapshots(VSS_ID SnapshotSetId)
335 {
336     return S_OK;
337 }
338 
339 STDMETHODIMP CQGAVssProvider::CommitSnapshots(VSS_ID SnapshotSetId)
340 {
341     HRESULT hr = S_OK;
342     HANDLE hEventFrozen, hEventThaw, hEventTimeout;
343 
344     hEventFrozen = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_FROZEN);
345     if (hEventFrozen == INVALID_HANDLE_VALUE) {
346         return E_FAIL;
347     }
348 
349     hEventThaw = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_THAW);
350     if (hEventThaw == INVALID_HANDLE_VALUE) {
351         CloseHandle(hEventFrozen);
352         return E_FAIL;
353     }
354 
355     hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
356     if (hEventTimeout == INVALID_HANDLE_VALUE) {
357         CloseHandle(hEventFrozen);
358         CloseHandle(hEventThaw);
359         return E_FAIL;
360     }
361 
362     /* Send event to qemu-ga to notify filesystem is frozen */
363     SetEvent(hEventFrozen);
364 
365     /* Wait until the snapshot is taken by the host. */
366     if (WaitForSingleObject(hEventThaw, VSS_TIMEOUT_MSEC) != WAIT_OBJECT_0) {
367         /* Send event to qemu-ga to notify the provider is timed out */
368         SetEvent(hEventTimeout);
369         hr = E_ABORT;
370     }
371 
372     CloseHandle(hEventThaw);
373     CloseHandle(hEventFrozen);
374     CloseHandle(hEventTimeout);
375     return hr;
376 }
377 
378 STDMETHODIMP CQGAVssProvider::PostCommitSnapshots(
379     VSS_ID SnapshotSetId, LONG lSnapshotsCount)
380 {
381     return S_OK;
382 }
383 
384 STDMETHODIMP CQGAVssProvider::PreFinalCommitSnapshots(VSS_ID SnapshotSetId)
385 {
386     return S_OK;
387 }
388 
389 STDMETHODIMP CQGAVssProvider::PostFinalCommitSnapshots(VSS_ID SnapshotSetId)
390 {
391     return S_OK;
392 }
393 
394 STDMETHODIMP CQGAVssProvider::AbortSnapshots(VSS_ID SnapshotSetId)
395 {
396     return S_OK;
397 }
398 
399 /*
400  * IVssProviderNotifications methods
401  */
402 
403 STDMETHODIMP CQGAVssProvider::OnLoad(IUnknown *pCallback)
404 {
405     return S_OK;
406 }
407 
408 STDMETHODIMP CQGAVssProvider::OnUnload(BOOL bForceUnload)
409 {
410     return S_OK;
411 }
412 
413 
414 /*
415  * CQGAVssProviderFactory class
416  */
417 
418 class CQGAVssProviderFactory : public IClassFactory
419 {
420 public:
421     STDMETHODIMP QueryInterface(REFIID riid, void **ppv);
422     STDMETHODIMP_(ULONG) AddRef();
423     STDMETHODIMP_(ULONG) Release();
424     STDMETHODIMP CreateInstance(
425         IUnknown *pUnknownOuter, REFIID iid, void **ppv);
426     STDMETHODIMP LockServer(BOOL lock) { return E_NOTIMPL; }
427 
428     CQGAVssProviderFactory();
429     ~CQGAVssProviderFactory();
430 
431 private:
432     long m_nRefCount;
433 };
434 
435 CQGAVssProviderFactory::CQGAVssProviderFactory()
436 {
437     m_nRefCount = 0;
438     LockModule(TRUE);
439 }
440 
441 CQGAVssProviderFactory::~CQGAVssProviderFactory()
442 {
443     LockModule(FALSE);
444 }
445 
446 STDMETHODIMP CQGAVssProviderFactory::QueryInterface(REFIID riid, void **ppv)
447 {
448     if (riid == IID_IUnknown || riid == IID_IClassFactory) {
449         *ppv = static_cast<void*>(this);
450         AddRef();
451         return S_OK;
452     }
453     *ppv = NULL;
454     return E_NOINTERFACE;
455 }
456 
457 STDMETHODIMP_(ULONG) CQGAVssProviderFactory::AddRef()
458 {
459     return InterlockedIncrement(&m_nRefCount);
460 }
461 
462 STDMETHODIMP_(ULONG) CQGAVssProviderFactory::Release()
463 {
464     long nRefCount = InterlockedDecrement(&m_nRefCount);
465     if (m_nRefCount == 0) {
466         delete this;
467     }
468     return nRefCount;
469 }
470 
471 STDMETHODIMP CQGAVssProviderFactory::CreateInstance(
472     IUnknown *pUnknownOuter, REFIID iid, void **ppv)
473 {
474     CQGAVssProvider *pObj;
475 
476     if (pUnknownOuter) {
477         return CLASS_E_NOAGGREGATION;
478     }
479     try {
480         pObj = new CQGAVssProvider;
481     } catch (...) {
482         return E_OUTOFMEMORY;
483     }
484     HRESULT hr = pObj->QueryInterface(iid, ppv);
485     if (FAILED(hr)) {
486         delete pObj;
487     }
488     return hr;
489 }
490 
491 
492 /*
493  * DLL functions
494  */
495 
496 STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
497 {
498     CQGAVssProviderFactory *factory;
499     try {
500         factory = new CQGAVssProviderFactory;
501     } catch (...) {
502         return E_OUTOFMEMORY;
503     }
504     factory->AddRef();
505     HRESULT hr = factory->QueryInterface(riid, ppv);
506     factory->Release();
507     return hr;
508 }
509 
510 STDAPI DllCanUnloadNow()
511 {
512     return g_nComObjsInUse == 0 ? S_OK : S_FALSE;
513 }
514 
515 EXTERN_C
516 BOOL WINAPI DllMain(HINSTANCE hinstDll, DWORD dwReason, LPVOID lpReserved)
517 {
518     if (dwReason == DLL_PROCESS_ATTACH) {
519         g_hinstDll = hinstDll;
520         DisableThreadLibraryCalls(hinstDll);
521     }
522     return TRUE;
523 }
524