/* $Id: shmem-win.cpp $ */ /** @file * IPRT - Named shared memory object, Windows Implementation. */ /* * Copyright (C) 2018-2019 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include #include #include "internal/iprt.h" #include #include #include #include #include #include #include #include "internal/magics.h" #include "internal/path.h" #include "internal-r3-win.h" /* For g_enmWinVer + kRTWinOSType_XXX */ /* * Define values ourselves in case the compiling host is too old. * See https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-createfilemappinga * for when these were introduced. */ #ifndef PAGE_EXECUTE_READ # define PAGE_EXECUTE_READ 0x20 #endif #ifndef PAGE_EXECUTE_READWRITE # define PAGE_EXECUTE_READWRITE 0x40 #endif #ifndef PAGE_EXECUTE_WRITECOPY # define PAGE_EXECUTE_WRITECOPY 0x80 #endif #ifndef FILE_MAP_EXECUTE # define FILE_MAP_EXECUTE 0x20 #endif /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ /** * Shared memory object mapping descriptor. */ typedef struct RTSHMEMMAPPINGDESC { /** Number of references held to this mapping, 0 if the descriptor is free. */ volatile uint32_t cMappings; /** Pointer to the region mapping. */ void *pvMapping; /** Start offset */ size_t offRegion; /** Size of the region. */ size_t cbRegion; /** Access flags for this region .*/ uint32_t fFlags; } RTSHMEMMAPPINGDESC; /** Pointer to a shared memory object mapping descriptor. */ typedef RTSHMEMMAPPINGDESC *PRTSHMEMMAPPINGDESC; /** Pointer to a constant shared memory object mapping descriptor. */ typedef const RTSHMEMMAPPINGDESC *PCRTSHMEMMAPPINGDESC; /** * Internal shared memory object state. */ typedef struct RTSHMEMINT { /** Magic value (RTSHMEM_MAGIC). */ uint32_t u32Magic; /** Flag whether this instance created the named shared memory object. */ bool fCreate; /** Handle to the underlying mapping object. */ HANDLE hShmObj; /** Size of the mapping object in bytes. */ size_t cbMax; /** Overall number of mappings active for this shared memory object. */ volatile uint32_t cMappings; /** Maximum number of mapping descriptors allocated. */ uint32_t cMappingDescsMax; /** Number of mapping descriptors used. */ volatile uint32_t cMappingDescsUsed; /** Array of mapping descriptors - variable in size. */ RTSHMEMMAPPINGDESC aMappingDescs[1]; } RTSHMEMINT; /** Pointer to the internal shared memory object state. */ typedef RTSHMEMINT *PRTSHMEMINT; /** * Returns a mapping descriptor matching the given region properties or NULL if none was found. * * @returns Pointer to the matching mapping descriptor or NULL if not found. * @param pThis Pointer to the shared memory object instance. * @param offRegion Offset into the shared memory object to start mapping at. * @param cbRegion Size of the region to map. * @param fFlags Desired properties of the mapped region, combination of RTSHMEM_MAP_F_* defines. */ DECLINLINE(PRTSHMEMMAPPINGDESC) rtShMemMappingDescFindByProp(PRTSHMEMINT pThis, size_t offRegion, size_t cbRegion, uint32_t fFlags) { for (uint32_t i = 0; i < pThis->cMappingDescsMax; i++) { if ( pThis->aMappingDescs[i].offRegion == offRegion && pThis->aMappingDescs[i].cbRegion == cbRegion && pThis->aMappingDescs[i].fFlags == fFlags) return &pThis->aMappingDescs[i]; } return NULL; } RTDECL(int) RTShMemOpen(PRTSHMEM phShMem, const char *pszName, uint32_t fFlags, size_t cbMax, uint32_t cMappingsHint) { AssertPtrReturn(phShMem, VERR_INVALID_PARAMETER); AssertPtrReturn(pszName, VERR_INVALID_PARAMETER); AssertReturn(!(fFlags & ~RTSHMEM_O_F_VALID_MASK), VERR_INVALID_PARAMETER); AssertReturn(cMappingsHint < 64, VERR_OUT_OF_RANGE); AssertReturn(cbMax > 0 || !(fFlags & RTSHMEM_O_F_CREATE), VERR_NOT_SUPPORTED); if (fFlags & RTSHMEM_O_F_TRUNCATE) return VERR_NOT_SUPPORTED; /* * The executable access was introduced with Windows XP SP2 and Windows Server 2003 SP1, * PAGE_EXECUTE_WRITECOPY was not available until Windows Vista SP1. * Allow execute mappings only starting from Windows 7 to keep the checks simple here (lazy coder). */ if ( (fFlags & RTSHMEM_O_F_MAYBE_EXEC) && g_enmWinVer < kRTWinOSType_7) return VERR_NOT_SUPPORTED; cMappingsHint = cMappingsHint == 0 ? 5 : cMappingsHint; int rc = VINF_SUCCESS; PRTSHMEMINT pThis = (PRTSHMEMINT)RTMemAllocZ(RT_UOFFSETOF_DYN(RTSHMEMINT, aMappingDescs[cMappingsHint])); if (RT_LIKELY(pThis)) { pThis->u32Magic = RTSHMEM_MAGIC; /*pThis->fCreate = false; */ /*pThis->cMappings = 0; */ pThis->cMappingDescsMax = cMappingsHint; /*pThis->cMappingDescsUsed = 0; */ /* Construct the filename, always use the local namespace, global requires special privileges. */ char szName[RTPATH_MAX]; ssize_t cch = RTStrPrintf2(&szName[0], sizeof(szName), "Local\\%s", pszName); if (cch > 0) { PRTUTF16 pwszName = NULL; rc = RTStrToUtf16Ex(&szName[0], RTSTR_MAX, &pwszName, 0, NULL); if (RT_SUCCESS(rc)) { if (fFlags & RTSHMEM_O_F_CREATE) { #if HC_ARCH_BITS == 64 DWORD dwSzMaxHigh = cbMax >> 32; #elif HC_ARCH_BITS == 32 DWORD dwSzMaxHigh = 0; #else # error "Port me" #endif DWORD dwSzMaxLow = cbMax & UINT32_C(0xffffffff); DWORD fProt = 0; if (fFlags & RTSHMEM_O_F_MAYBE_EXEC) { if ((fFlags & RTSHMEM_O_F_READWRITE) == RTSHMEM_O_F_READ) fProt |= PAGE_EXECUTE_READ; else fProt |= PAGE_EXECUTE_READWRITE; } else { if ((fFlags & RTSHMEM_O_F_READWRITE) == RTSHMEM_O_F_READ) fProt |= PAGE_READONLY; else fProt |= PAGE_READWRITE; } pThis->hShmObj = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL, fProt, dwSzMaxHigh, dwSzMaxLow, pwszName); } else { DWORD fProt = SECTION_QUERY; if (fFlags & RTSHMEM_O_F_MAYBE_EXEC) fProt |= FILE_MAP_EXECUTE; if (fFlags & RTSHMEM_O_F_READ) fProt |= FILE_MAP_READ; if (fFlags & RTSHMEM_O_F_WRITE) fProt |= FILE_MAP_WRITE; pThis->hShmObj = OpenFileMappingW(fProt, FALSE, pwszName); } RTUtf16Free(pwszName); if (pThis->hShmObj != NULL) { *phShMem = pThis; return VINF_SUCCESS; } else rc = RTErrConvertFromWin32(GetLastError()); } } else rc = VERR_BUFFER_OVERFLOW; RTMemFree(pThis); } else rc = VERR_NO_MEMORY; return rc; } RTDECL(int) RTShMemClose(RTSHMEM hShMem) { PRTSHMEMINT pThis = hShMem; AssertPtrReturn(pThis, VERR_INVALID_PARAMETER); AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE); AssertReturn(!pThis->cMappings, VERR_INVALID_STATE); int rc = VINF_SUCCESS; if (CloseHandle(pThis->hShmObj)) { pThis->u32Magic = RTSHMEM_MAGIC_DEAD; RTMemFree(pThis); } else rc = RTErrConvertFromWin32(GetLastError()); return rc; } RTDECL(uint32_t) RTShMemRefCount(RTSHMEM hShMem) { PRTSHMEMINT pThis = hShMem; AssertPtrReturn(pThis, 0); AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, 0); return pThis->cMappings; } RTDECL(int) RTShMemSetSize(RTSHMEM hShMem, size_t cbMem) { PRTSHMEMINT pThis = hShMem; AssertPtrReturn(pThis, VERR_INVALID_PARAMETER); AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE); AssertReturn(!pThis->cMappings, VERR_INVALID_STATE); AssertReturn(cbMem, VERR_NOT_SUPPORTED); return VERR_NOT_SUPPORTED; } RTDECL(int) RTShMemQuerySize(RTSHMEM hShMem, size_t *pcbMem) { PRTSHMEMINT pThis = hShMem; AssertPtrReturn(pThis, VERR_INVALID_PARAMETER); AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE); AssertPtrReturn(pcbMem, VERR_INVALID_PARAMETER); int rc = VINF_SUCCESS; SECTION_BASIC_INFORMATION SecInf; SIZE_T cbRet; NTSTATUS rcNt = NtQuerySection(pThis->hShmObj, SectionBasicInformation, &SecInf, sizeof(SecInf), &cbRet); if (NT_SUCCESS(rcNt)) { AssertReturn(cbRet == sizeof(SecInf), VERR_INTERNAL_ERROR); #if HC_ARCH_BITS == 32 AssertReturn(SecInf.MaximumSize.HighPart == 0, VERR_INTERNAL_ERROR_2); *pcbMem = SecInf.MaximumSize.LowPart; #elif HC_ARCH_BITS == 64 *pcbMem = SecInf.MaximumSize.QuadPart; #else # error "Port me" #endif } else rc = RTErrConvertFromNtStatus(rcNt); return rc; } RTDECL(int) RTShMemMapRegion(RTSHMEM hShMem, size_t offRegion, size_t cbRegion, uint32_t fFlags, void **ppv) { PRTSHMEMINT pThis = hShMem; AssertPtrReturn(pThis, VERR_INVALID_PARAMETER); AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE); AssertPtrReturn(ppv, VERR_INVALID_PARAMETER); AssertReturn(!(fFlags & ~RTSHMEM_MAP_F_VALID_MASK), VERR_INVALID_PARAMETER); /* See comment in RTShMemOpen(). */ if ( (fFlags & RTSHMEM_MAP_F_EXEC) && g_enmWinVer < kRTWinOSType_7) return VERR_NOT_SUPPORTED; /* Try to find a mapping with compatible parameters first. */ PRTSHMEMMAPPINGDESC pMappingDesc = NULL; for (uint32_t iTry = 0; iTry < 10; iTry++) { pMappingDesc = rtShMemMappingDescFindByProp(pThis, offRegion, cbRegion, fFlags); if (!pMappingDesc) break; /* Increase the mapping count and check that the region is still accessible by us. */ if ( ASMAtomicIncU32(&pMappingDesc->cMappings) > 1 && pMappingDesc->offRegion == offRegion && pMappingDesc->cbRegion == cbRegion && pMappingDesc->fFlags == fFlags) break; /* Mapping was freed inbetween, next round. */ } int rc = VINF_SUCCESS; if (!pMappingDesc) { /* Find an empty region descriptor and map the region. */ for (uint32_t i = 0; i < pThis->cMappingDescsMax && !pMappingDesc; i++) { if (!pThis->aMappingDescs[i].cMappings) { pMappingDesc = &pThis->aMappingDescs[i]; /* Try to grab this one. */ if (ASMAtomicIncU32(&pMappingDesc->cMappings) == 1) break; /* Somebody raced us, drop reference and continue. */ ASMAtomicDecU32(&pMappingDesc->cMappings); pMappingDesc = NULL; } } if (RT_LIKELY(pMappingDesc)) { /* Try to map it. */ DWORD fProt = 0; DWORD offLow = offRegion & UINT32_C(0xffffffff); #if HC_ARCH_BITS == 64 DWORD offHigh = offRegion >> 32; #elif HC_ARCH_BITS == 32 DWORD offHigh = 0; #else # error "Port me" #endif if (fFlags & RTSHMEM_MAP_F_READ) fProt |= FILE_MAP_READ; if (fFlags & RTSHMEM_MAP_F_WRITE) fProt |= FILE_MAP_WRITE; if (fFlags & RTSHMEM_MAP_F_EXEC) fProt |= FILE_MAP_EXECUTE; if (fFlags & RTSHMEM_MAP_F_COW) fProt |= FILE_MAP_COPY; void *pv = MapViewOfFile(pThis->hShmObj, fProt, offHigh, offLow, cbRegion); if (pv != NULL) { pMappingDesc->pvMapping = pv; pMappingDesc->offRegion = offRegion; pMappingDesc->cbRegion = cbRegion; pMappingDesc->fFlags = fFlags; } else { rc = RTErrConvertFromWin32(GetLastError()); ASMAtomicDecU32(&pMappingDesc->cMappings); } } else rc = VERR_SHMEM_MAXIMUM_MAPPINGS_REACHED; } if (RT_SUCCESS(rc)) { *ppv = pMappingDesc->pvMapping; ASMAtomicIncU32(&pThis->cMappings); } return rc; } RTDECL(int) RTShMemUnmapRegion(RTSHMEM hShMem, void *pv) { PRTSHMEMINT pThis = hShMem; AssertPtrReturn(pThis, VERR_INVALID_PARAMETER); AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE); AssertPtrReturn(pv, VERR_INVALID_PARAMETER); /* Find the mapping descriptor by the given region address. */ PRTSHMEMMAPPINGDESC pMappingDesc = NULL; for (uint32_t i = 0; i < pThis->cMappingDescsMax && !pMappingDesc; i++) { if (pThis->aMappingDescs[i].pvMapping == pv) { pMappingDesc = &pThis->aMappingDescs[i]; break; } } AssertPtrReturn(pMappingDesc, VERR_INVALID_PARAMETER); int rc = VINF_SUCCESS; if (!ASMAtomicDecU32(&pMappingDesc->cMappings)) { /* Last mapping of this region was unmapped, so do the real unmapping now. */ if (UnmapViewOfFile(pv)) { ASMAtomicDecU32(&pThis->cMappingDescsUsed); ASMAtomicDecU32(&pThis->cMappings); } else { ASMAtomicIncU32(&pMappingDesc->cMappings); rc = RTErrConvertFromWin32(GetLastError()); } } return rc; }