Index: /trunk/src/VBox/Storage/VHD.cpp =================================================================== --- /trunk/src/VBox/Storage/VHD.cpp (revision 39576) +++ /trunk/src/VBox/Storage/VHD.cpp (revision 39577) @@ -3036,4 +3036,344 @@ } /* Same size doesn't change the image at all. */ + + LogFlowFunc(("returns %Rrc\n", rc)); + return rc; +} + +/** @copydoc VBOXHDDBACKEND::pfnRepair */ +static DECLCALLBACK(int) vhdRepair(const char *pszFilename, PVDINTERFACE pVDIfsDisk, + PVDINTERFACE pVDIfsImage, uint32_t fFlags) +{ + LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage)); + int rc; + PVDINTERFACEERROR pIfError; + PVDINTERFACEIOINT pIfIo; + PVDIOSTORAGE pStorage; + uint64_t cbFile; + VHDFooter vhdFooter; + VHDDynamicDiskHeader dynamicDiskHeader; + uint32_t *paBat = NULL; + uint32_t *pu32BlockBitmap = NULL; + + pIfIo = VDIfIoIntGet(pVDIfsImage); + AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER); + + pIfError = VDIfErrorGet(pVDIfsDisk); + + do + { + uint64_t offDynamicDiskHeader = 0; + uint64_t offBat = 0; + uint64_t offFooter = 0; + uint32_t cBatEntries = 0; + bool fDynamic = false; + bool fRepairFooter = false; + bool fRepairBat = false; + bool fRepairDynHeader = false; + + rc = vdIfIoIntFileOpen(pIfIo, pszFilename, + VDOpenFlagsToFileOpenFlags( fFlags & VD_REPAIR_DRY_RUN + ? VD_OPEN_FLAGS_READONLY + : 0, + false /* fCreate */), + &pStorage); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to open image \"%s\"", pszFilename); + break; + } + + rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to query image size"); + break; + } + + if (cbFile < sizeof(VHDFooter)) + { + rc = vdIfError(pIfError, VERR_VD_INVALID_SIZE, RT_SRC_POS, + "Image must be at least %u bytes (got %llu)", + sizeof(VHDFooter), cbFile); + break; + } + + rc = vdIfIoIntFileReadSync(pIfIo, pStorage, cbFile - sizeof(VHDFooter), + &vhdFooter, sizeof(VHDFooter), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to read footer of image"); + break; + } + + if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0) + { + /* Dynamic images have a backup at the beginning of the image. */ + rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, + &vhdFooter, sizeof(VHDFooter), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to read header of image"); + break; + } + + /* + * Check for the header, if this fails the image is either completely corrupted + * and impossible to repair or in another format. + */ + if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "No valid VHD structures found"); + break; + } + else + vdIfErrorMessage(pIfError, "Missing footer structure, using backup"); + + /* Remember to fix the footer structure. */ + fRepairFooter = true; + } + + offFooter = cbFile - sizeof(VHDFooter); + + /* Verify that checksums match. */ + uint32_t u32ChkSumOld = RT_BE2H_U32(vhdFooter.Checksum); + vhdFooter.Checksum = 0; + uint32_t u32ChkSum = vhdChecksum(&vhdFooter, sizeof(VHDFooter)); + + vhdFooter.Checksum = RT_H2BE_U32(u32ChkSum); + + if (u32ChkSumOld != u32ChkSum) + { + vdIfErrorMessage(pIfError, "Checksum is invalid (should be %u got %u), repairing", + u32ChkSum, u32ChkSumOld); + fRepairFooter = true; + break; + } + + switch (RT_BE2H_U32(vhdFooter.DiskType)) + { + case VHD_FOOTER_DISK_TYPE_FIXED: + fDynamic = false; + break; + case VHD_FOOTER_DISK_TYPE_DYNAMIC: + fDynamic = true; + break; + case VHD_FOOTER_DISK_TYPE_DIFFERENCING: + fDynamic = true; + break; + default: + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "VHD image type %u is not supported", + RT_BE2H_U32(vhdFooter.DiskType)); + break; + } + } + + /* Load and check dynamic disk header if required. */ + if (fDynamic) + { + size_t cbBlock; + + offDynamicDiskHeader = RT_BE2H_U64(vhdFooter.DataOffset); + if (offDynamicDiskHeader + sizeof(VHDDynamicDiskHeader) > cbFile) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "VHD image type is not supported"); + break; + } + + rc = vdIfIoIntFileReadSync(pIfIo, pStorage, offDynamicDiskHeader, + &dynamicDiskHeader, sizeof(VHDDynamicDiskHeader), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Failed to read dynamic disk header (at %llu), %Rrc", + offDynamicDiskHeader, rc); + break; + } + + /* Verify that checksums match. */ + u32ChkSumOld = RT_BE2H_U32(dynamicDiskHeader.Checksum); + dynamicDiskHeader.Checksum = 0; + u32ChkSum = vhdChecksum(&dynamicDiskHeader, sizeof(VHDDynamicDiskHeader)); + + dynamicDiskHeader.Checksum = RT_H2BE_U32(u32ChkSum); + + if (u32ChkSumOld != u32ChkSum) + { + vdIfErrorMessage(pIfError, "Checksum of dynamic disk header is invalid (should be %u got %u), repairing", + u32ChkSum, u32ChkSumOld); + fRepairDynHeader = true; + break; + } + + /* Read the block allocation table and fix any inconsistencies. */ + offBat = RT_BE2H_U64(dynamicDiskHeader.TableOffset); + cBatEntries = RT_BE2H_U32(dynamicDiskHeader.MaxTableEntries); + cbBlock = RT_BE2H_U32(dynamicDiskHeader.BlockSize); + cbBlock += cbBlock / VHD_SECTOR_SIZE / 8; + + if (offBat + cBatEntries * sizeof(uint32_t) > cbFile) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Block allocation table is not inside the image"); + break; + } + + paBat = (uint32_t *)RTMemAllocZ(cBatEntries * sizeof(uint32_t)); + if (!paBat) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Could not allocate memory for the block allocation table (%u bytes)", + cBatEntries * sizeof(uint32_t)); + break; + } + + rc = vdIfIoIntFileReadSync(pIfIo, pStorage, offBat, paBat, + cBatEntries * sizeof(uint32_t), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Could not read block allocation table (at %llu), %Rrc", + offBat, rc); + break; + } + + pu32BlockBitmap = (uint32_t *)RTMemAllocZ(RT_ALIGN_Z(cBatEntries, 4)); + if (!pu32BlockBitmap) + { + rc = vdIfError(pIfError, VERR_NO_MEMORY, RT_SRC_POS, + "Failed to allocate memory for block bitmap"); + break; + } + + uint32_t idxMinBlock = UINT32_C(0xffffffff); + for (uint32_t i = 0; i < cBatEntries; i++) + { + paBat[i] = RT_BE2H_U32(paBat[i]); + if (paBat[i] < idxMinBlock) + idxMinBlock = paBat[i]; + } + + vdIfErrorMessage(pIfError, "First data block at sector %u", idxMinBlock); + + for (uint32_t i = 0; i < cBatEntries; i++) + { + if (paBat[i] != UINT32_C(0xffffffff)) + { + uint64_t offBlock =(uint64_t)paBat[i] * VHD_SECTOR_SIZE; + + /* + * Check that the offsets are valid (inside of the image) and + * that there are no double references. + */ + if (offBlock + cbBlock > cbFile) + { + vdIfErrorMessage(pIfError, "Entry %u points to invalid offset %llu, clearing", + i, offBlock); + paBat[i] = 0; + fRepairBat = true; + } + else if (offBlock + cbBlock > offFooter) + { + vdIfErrorMessage(pIfError, "Entry %u intersects with footer, aligning footer", + i); + offFooter = offBlock + cbBlock; + fRepairBat = true; + } + + if (ASMBitTestAndSet(pu32BlockBitmap, (paBat[i] - idxMinBlock) / (cbBlock / VHD_SECTOR_SIZE))) + { + vdIfErrorMessage(pIfError, "Entry %u points to an already referenced data block, clearing", + i); + paBat[i] = 0; + fRepairBat = true; + } + } + } + } + + /* Write repaired structures now. */ + if (!(fRepairBat || fRepairDynHeader || fRepairFooter)) + vdIfErrorMessage(pIfError, "VHD image is in a consistent state, no repair required"); + else if (!(fFlags & VD_REPAIR_DRY_RUN)) + { + if (fRepairBat) + { + for (uint32_t i = 0; i < cBatEntries; i++) + paBat[i] = RT_H2BE_U32(paBat[i]); + + vdIfErrorMessage(pIfError, "Writing repaired block allocation table..."); + + rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, offBat, paBat, + cBatEntries * sizeof(uint32_t), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Could not write repaired block allocation table (at %llu), %Rrc", + offBat, rc); + break; + } + } + + if (fRepairDynHeader) + { + Assert(fDynamic); + + vdIfErrorMessage(pIfError, "Writing repaired dynamic disk header..."); + rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, offDynamicDiskHeader, &dynamicDiskHeader, + sizeof(VHDDynamicDiskHeader), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Could not write repaired dynamic disk header (at %llu), %Rrc", + offDynamicDiskHeader, rc); + break; + } + } + + if (fRepairFooter) + { + vdIfErrorMessage(pIfError, "Writing repaired Footer..."); + + if (fDynamic) + { + /* Write backup at image beginning. */ + rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, 0, &vhdFooter, + sizeof(VHDFooter), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Could not write repaired backup footer (at %llu), %Rrc", + 0, rc); + break; + } + } + + rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, offFooter, &vhdFooter, + sizeof(VHDFooter), NULL); + if (RT_FAILURE(rc)) + { + rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS, + "Could not write repaired footer (at %llu), %Rrc", + cbFile - sizeof(VHDFooter), rc); + break; + } + } + + vdIfErrorMessage(pIfError, "Corrupted VHD image repaired successfully"); + } + } while(0); + + if (paBat) + RTMemFree(paBat); + + if (pu32BlockBitmap) + RTMemFree(pu32BlockBitmap); + + if (pStorage) + vdIfIoIntFileClose(pIfIo, pStorage); LogFlowFunc(("returns %Rrc\n", rc)); @@ -3145,4 +3485,4 @@ NULL, /* pfnRepair */ - NULL + vhdRepair };