qga/vss-win32/provider.cpp

   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     *plDeletedSnapshots = 0;
 282     *pNondeletedSnapshotID = SourceObjectId;
 283     return S_OK;
 284 }
 285
 286 STDMETHODIMP CQGAVssProvider::BeginPrepareSnapshot(
 287     VSS_ID SnapshotSetId, VSS_ID SnapshotId,
 288     VSS_PWSZ pwszVolumeName, LONG lNewContext)
 289 {
 290     return S_OK;
 291 }
 292
 293 STDMETHODIMP CQGAVssProvider::IsVolumeSupported(
 294     VSS_PWSZ pwszVolumeName, BOOL *pbSupportedByThisProvider)
 295 {
 296     HANDLE hEventFrozen;
 297
 298     /* Check if a requester is qemu-ga by whether an event is created */
 299     hEventFrozen = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_FROZEN);
 300     if (!hEventFrozen) {
 301         *pbSupportedByThisProvider = FALSE;
 302         return S_OK;
 303     }
 304     CloseHandle(hEventFrozen);
 305
 306     *pbSupportedByThisProvider = TRUE;
 307     return S_OK;
 308 }
 309
 310 STDMETHODIMP CQGAVssProvider::IsVolumeSnapshotted(VSS_PWSZ pwszVolumeName,
 311     BOOL *pbSnapshotsPresent, LONG *plSnapshotCompatibility)
 312 {
 313     *pbSnapshotsPresent = FALSE;
 314     *plSnapshotCompatibility = 0;
 315     return S_OK;
 316 }
 317
 318 STDMETHODIMP CQGAVssProvider::SetSnapshotProperty(VSS_ID SnapshotId,
 319     VSS_SNAPSHOT_PROPERTY_ID eSnapshotPropertyId, VARIANT vProperty)
 320 {
 321     return E_NOTIMPL;
 322 }
 323
 324 STDMETHODIMP CQGAVssProvider::RevertToSnapshot(VSS_ID SnapshotId)
 325 {
 326     return E_NOTIMPL;
 327 }
 328
 329 STDMETHODIMP CQGAVssProvider::QueryRevertStatus(
 330     VSS_PWSZ pwszVolume, IVssAsync **ppAsync)
 331 {
 332     return E_NOTIMPL;
 333 }
 334
 335
 336 /*
 337  * IVssProviderCreateSnapshotSet methods
 338  */
 339
 340 STDMETHODIMP CQGAVssProvider::EndPrepareSnapshots(VSS_ID SnapshotSetId)
 341 {
 342     return S_OK;
 343 }
 344
 345 STDMETHODIMP CQGAVssProvider::PreCommitSnapshots(VSS_ID SnapshotSetId)
 346 {
 347     return S_OK;
 348 }
 349
 350 STDMETHODIMP CQGAVssProvider::CommitSnapshots(VSS_ID SnapshotSetId)
 351 {
 352     HRESULT hr = S_OK;
 353     HANDLE hEventFrozen, hEventThaw, hEventTimeout;
 354
 355     hEventFrozen = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_FROZEN);
 356     if (!hEventFrozen) {
 357         return E_FAIL;
 358     }
 359
 360     hEventThaw = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_THAW);
 361     if (!hEventThaw) {
 362         CloseHandle(hEventFrozen);
 363         return E_FAIL;
 364     }
 365
 366     hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
 367     if (!hEventTimeout) {
 368         CloseHandle(hEventFrozen);
 369         CloseHandle(hEventThaw);
 370         return E_FAIL;
 371     }
 372
 373     /* Send event to qemu-ga to notify filesystem is frozen */
 374     SetEvent(hEventFrozen);
 375
 376     /* Wait until the snapshot is taken by the host. */
 377     if (WaitForSingleObject(hEventThaw, VSS_TIMEOUT_MSEC) != WAIT_OBJECT_0) {
 378         /* Send event to qemu-ga to notify the provider is timed out */
 379         SetEvent(hEventTimeout);
 380         hr = E_ABORT;
 381     }
 382
 383     CloseHandle(hEventThaw);
 384     CloseHandle(hEventFrozen);
 385     CloseHandle(hEventTimeout);
 386     return hr;
 387 }
 388
 389 STDMETHODIMP CQGAVssProvider::PostCommitSnapshots(
 390     VSS_ID SnapshotSetId, LONG lSnapshotsCount)
 391 {
 392     return S_OK;
 393 }
 394
 395 STDMETHODIMP CQGAVssProvider::PreFinalCommitSnapshots(VSS_ID SnapshotSetId)
 396 {
 397     return S_OK;
 398 }
 399
 400 STDMETHODIMP CQGAVssProvider::PostFinalCommitSnapshots(VSS_ID SnapshotSetId)
 401 {
 402     return S_OK;
 403 }
 404
 405 STDMETHODIMP CQGAVssProvider::AbortSnapshots(VSS_ID SnapshotSetId)
 406 {
 407     return S_OK;
 408 }
 409
 410 /*
 411  * IVssProviderNotifications methods
 412  */
 413
 414 STDMETHODIMP CQGAVssProvider::OnLoad(IUnknown *pCallback)
 415 {
 416     return S_OK;
 417 }
 418
 419 STDMETHODIMP CQGAVssProvider::OnUnload(BOOL bForceUnload)
 420 {
 421     return S_OK;
 422 }
 423
 424
 425 /*
 426  * CQGAVssProviderFactory class
 427  */
 428
 429 class CQGAVssProviderFactory : public IClassFactory
 430 {
 431 public:
 432     STDMETHODIMP QueryInterface(REFIID riid, void **ppv);
 433     STDMETHODIMP_(ULONG) AddRef();
 434     STDMETHODIMP_(ULONG) Release();
 435     STDMETHODIMP CreateInstance(
 436         IUnknown *pUnknownOuter, REFIID iid, void **ppv);
 437     STDMETHODIMP LockServer(BOOL lock) { return E_NOTIMPL; }
 438
 439     CQGAVssProviderFactory();
 440     ~CQGAVssProviderFactory();
 441
 442 private:
 443     long m_nRefCount;
 444 };
 445
 446 CQGAVssProviderFactory::CQGAVssProviderFactory()
 447 {
 448     m_nRefCount = 0;
 449     LockModule(TRUE);
 450 }
 451
 452 CQGAVssProviderFactory::~CQGAVssProviderFactory()
 453 {
 454     LockModule(FALSE);
 455 }
 456
 457 STDMETHODIMP CQGAVssProviderFactory::QueryInterface(REFIID riid, void **ppv)
 458 {
 459     if (riid == IID_IUnknown || riid == IID_IClassFactory) {
 460         *ppv = static_cast<void*>(this);
 461         AddRef();
 462         return S_OK;
 463     }
 464     *ppv = NULL;
 465     return E_NOINTERFACE;
 466 }
 467
 468 STDMETHODIMP_(ULONG) CQGAVssProviderFactory::AddRef()
 469 {
 470     return InterlockedIncrement(&m_nRefCount);
 471 }
 472
 473 STDMETHODIMP_(ULONG) CQGAVssProviderFactory::Release()
 474 {
 475     long nRefCount = InterlockedDecrement(&m_nRefCount);
 476     if (m_nRefCount == 0) {
 477         delete this;
 478     }
 479     return nRefCount;
 480 }
 481
 482 STDMETHODIMP CQGAVssProviderFactory::CreateInstance(
 483     IUnknown *pUnknownOuter, REFIID iid, void **ppv)
 484 {
 485     CQGAVssProvider *pObj;
 486
 487     if (pUnknownOuter) {
 488         return CLASS_E_NOAGGREGATION;
 489     }
 490     try {
 491         pObj = new CQGAVssProvider;
 492     } catch (...) {
 493         return E_OUTOFMEMORY;
 494     }
 495     HRESULT hr = pObj->QueryInterface(iid, ppv);
 496     if (FAILED(hr)) {
 497         delete pObj;
 498     }
 499     return hr;
 500 }
 501
 502
 503 /*
 504  * DLL functions
 505  */
 506
 507 STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
 508 {
 509     CQGAVssProviderFactory *factory;
 510     try {
 511         factory = new CQGAVssProviderFactory;
 512     } catch (...) {
 513         return E_OUTOFMEMORY;
 514     }
 515     factory->AddRef();
 516     HRESULT hr = factory->QueryInterface(riid, ppv);
 517     factory->Release();
 518     return hr;
 519 }
 520
 521 STDAPI DllCanUnloadNow()
 522 {
 523     return g_nComObjsInUse == 0 ? S_OK : S_FALSE;
 524 }
 525
 526 EXTERN_C
 527 BOOL WINAPI DllMain(HINSTANCE hinstDll, DWORD dwReason, LPVOID lpReserved)
 528 {
 529     if (dwReason == DLL_PROCESS_ATTACH) {
 530         g_hinstDll = hinstDll;
 531         DisableThreadLibraryCalls(hinstDll);
 532     }
 533     return TRUE;
 534 }