/* $Id: vfsstdfile.cpp 73097 2018-07-12 21:06:33Z vboxsync $ */ /** @file * IPRT - Virtual File System, Standard File Implementation. */ /* * Copyright (C) 2010-2017 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 #include #include #include #include #include /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ /** * Private data of a standard file. */ typedef struct RTVFSSTDFILE { /** The file handle. */ RTFILE hFile; /** Whether to leave the handle open when the VFS handle is closed. */ bool fLeaveOpen; } RTVFSSTDFILE; /** Pointer to the private data of a standard file. */ typedef RTVFSSTDFILE *PRTVFSSTDFILE; /** * @interface_method_impl{RTVFSOBJOPS,pfnClose} */ static DECLCALLBACK(int) rtVfsStdFile_Close(void *pvThis) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; int rc; if (!pThis->fLeaveOpen) rc = RTFileClose(pThis->hFile); else rc = VINF_SUCCESS; pThis->hFile = NIL_RTFILE; return rc; } /** * @interface_method_impl{RTVFSOBJOPS,pfnQueryInfo} */ static DECLCALLBACK(int) rtVfsStdFile_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; return RTFileQueryInfo(pThis->hFile, pObjInfo, enmAddAttr); } /** * RTFileRead and RTFileReadAt does not return VINF_EOF or VINF_TRY_AGAIN, this * function tries to fix this as best as it can. * * This fixing can be subject to races if some other thread or process is * modifying the file size between the read and our size query here. * * @returns VINF_SUCCESS, VINF_EOF or VINF_TRY_AGAIN. * @param pThis The instance data. * @param off The offset parameter. * @param cbToRead The number of bytes attempted read . * @param cbActuallyRead The number of bytes actually read. */ DECLINLINE(int) rtVfsStdFile_ReadFixRC(PRTVFSSTDFILE pThis, RTFOFF off, size_t cbToRead, size_t cbActuallyRead) { /* If the read returned less bytes than requested, it means the end of the file has been reached. */ if (cbToRead > cbActuallyRead) return VINF_EOF; /* The other case here is the very special zero byte read at the end of the file, where we're supposed to indicate EOF. */ if (cbToRead > 0) return VINF_SUCCESS; uint64_t cbFile; int rc = RTFileGetSize(pThis->hFile, &cbFile); if (RT_FAILURE(rc)) return rc; uint64_t off2; if (off >= 0) off2 = off; else { rc = RTFileSeek(pThis->hFile, 0, RTFILE_SEEK_CURRENT, &off2); if (RT_FAILURE(rc)) return rc; } return off2 >= cbFile ? VINF_EOF : VINF_SUCCESS; } /** * @interface_method_impl{RTVFSIOSTREAMOPS,pfnRead} */ static DECLCALLBACK(int) rtVfsStdFile_Read(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbRead) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; int rc; NOREF(fBlocking); if (pSgBuf->cSegs == 1) { if (off < 0) rc = RTFileRead( pThis->hFile, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbRead); else rc = RTFileReadAt(pThis->hFile, off, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbRead); if (rc == VINF_SUCCESS && pcbRead) rc = rtVfsStdFile_ReadFixRC(pThis, off, pSgBuf->paSegs[0].cbSeg, *pcbRead); } else { size_t cbSeg = 0; size_t cbRead = 0; size_t cbReadSeg = 0; rc = VINF_SUCCESS; for (uint32_t iSeg = 0; iSeg < pSgBuf->cSegs; iSeg++) { void *pvSeg = pSgBuf->paSegs[iSeg].pvSeg; cbSeg = pSgBuf->paSegs[iSeg].cbSeg; cbReadSeg = cbSeg; if (off < 0) rc = RTFileRead( pThis->hFile, pvSeg, cbSeg, pcbRead ? &cbReadSeg : NULL); else rc = RTFileReadAt(pThis->hFile, off, pvSeg, cbSeg, pcbRead ? &cbReadSeg : NULL); if (RT_FAILURE(rc)) break; if (off >= 0) off += cbReadSeg; cbRead += cbReadSeg; if ((pcbRead && cbReadSeg != cbSeg) || rc != VINF_SUCCESS) break; } if (pcbRead) { *pcbRead = cbRead; if (rc == VINF_SUCCESS) rc = rtVfsStdFile_ReadFixRC(pThis, off, cbSeg, cbReadSeg); } } return rc; } /** * @interface_method_impl{RTVFSIOSTREAMOPS,pfnWrite} */ static DECLCALLBACK(int) rtVfsStdFile_Write(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbWritten) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; int rc; NOREF(fBlocking); if (pSgBuf->cSegs == 1) { if (off < 0) rc = RTFileWrite(pThis->hFile, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbWritten); else rc = RTFileWriteAt(pThis->hFile, off, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbWritten); } else { size_t cbWritten = 0; size_t cbWrittenSeg; size_t *pcbWrittenSeg = pcbWritten ? &cbWrittenSeg : NULL; rc = VINF_SUCCESS; for (uint32_t iSeg = 0; iSeg < pSgBuf->cSegs; iSeg++) { void *pvSeg = pSgBuf->paSegs[iSeg].pvSeg; size_t cbSeg = pSgBuf->paSegs[iSeg].cbSeg; cbWrittenSeg = 0; if (off < 0) rc = RTFileWrite(pThis->hFile, pvSeg, cbSeg, pcbWrittenSeg); else { rc = RTFileWriteAt(pThis->hFile, off, pvSeg, cbSeg, pcbWrittenSeg); off += cbSeg; } if (RT_FAILURE(rc)) break; if (pcbWritten) { cbWritten += cbWrittenSeg; if (cbWrittenSeg != cbSeg) break; } } if (pcbWritten) *pcbWritten = cbWritten; } return rc; } /** * @interface_method_impl{RTVFSIOSTREAMOPS,pfnFlush} */ static DECLCALLBACK(int) rtVfsStdFile_Flush(void *pvThis) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; int rc = RTFileFlush(pThis->hFile); #ifdef RT_OS_WINDOWS /* Workaround for console handles. */ /** @todo push this further down? */ if ( rc == VERR_INVALID_HANDLE && RTFileIsValid(pThis->hFile)) rc = VINF_NOT_SUPPORTED; /* not flushable */ #endif return rc; } /** * @interface_method_impl{RTVFSIOSTREAMOPS,pfnPollOne} */ static DECLCALLBACK(int) rtVfsStdFile_PollOne(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents) { NOREF(pvThis); int rc; if (fEvents != RTPOLL_EVT_ERROR) { *pfRetEvents = fEvents & ~RTPOLL_EVT_ERROR; rc = VINF_SUCCESS; } else if (fIntr) rc = RTThreadSleep(cMillies); else { uint64_t uMsStart = RTTimeMilliTS(); do rc = RTThreadSleep(cMillies); while ( rc == VERR_INTERRUPTED && !fIntr && RTTimeMilliTS() - uMsStart < cMillies); if (rc == VERR_INTERRUPTED) rc = VERR_TIMEOUT; } return rc; } /** * @interface_method_impl{RTVFSIOSTREAMOPS,pfnTell} */ static DECLCALLBACK(int) rtVfsStdFile_Tell(void *pvThis, PRTFOFF poffActual) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; uint64_t offActual; int rc = RTFileSeek(pThis->hFile, 0, RTFILE_SEEK_CURRENT, &offActual); if (RT_SUCCESS(rc)) *poffActual = (RTFOFF)offActual; return rc; } /** * @interface_method_impl{RTVFSIOSTREAMOPS,pfnSkip} */ static DECLCALLBACK(int) rtVfsStdFile_Skip(void *pvThis, RTFOFF cb) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; uint64_t offIgnore; return RTFileSeek(pThis->hFile, cb, RTFILE_SEEK_CURRENT, &offIgnore); } /** * @interface_method_impl{RTVFSOBJSETOPS,pfnMode} */ static DECLCALLBACK(int) rtVfsStdFile_SetMode(void *pvThis, RTFMODE fMode, RTFMODE fMask) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; if (fMask != ~RTFS_TYPE_MASK) { #if 0 RTFMODE fCurMode; int rc = RTFileGetMode(pThis->hFile, &fCurMode); if (RT_FAILURE(rc)) return rc; fMode |= ~fMask & fCurMode; #else RTFSOBJINFO ObjInfo; int rc = RTFileQueryInfo(pThis->hFile, &ObjInfo, RTFSOBJATTRADD_NOTHING); if (RT_FAILURE(rc)) return rc; fMode |= ~fMask & ObjInfo.Attr.fMode; #endif } return RTFileSetMode(pThis->hFile, fMode); } /** * @interface_method_impl{RTVFSOBJSETOPS,pfnSetTimes} */ static DECLCALLBACK(int) rtVfsStdFile_SetTimes(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime, PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; return RTFileSetTimes(pThis->hFile, pAccessTime, pModificationTime, pChangeTime, pBirthTime); } /** * @interface_method_impl{RTVFSOBJSETOPS,pfnSetOwner} */ static DECLCALLBACK(int) rtVfsStdFile_SetOwner(void *pvThis, RTUID uid, RTGID gid) { #if 0 PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; return RTFileSetOwner(pThis->hFile, uid, gid); #else NOREF(pvThis); NOREF(uid); NOREF(gid); return VERR_NOT_IMPLEMENTED; #endif } /** * @interface_method_impl{RTVFSFILEOPS,pfnSeek} */ static DECLCALLBACK(int) rtVfsStdFile_Seek(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; uint64_t offActual = 0; int rc = RTFileSeek(pThis->hFile, offSeek, uMethod, &offActual); if (RT_SUCCESS(rc)) *poffActual = offActual; return rc; } /** * @interface_method_impl{RTVFSFILEOPS,pfnQuerySize} */ static DECLCALLBACK(int) rtVfsStdFile_QuerySize(void *pvThis, uint64_t *pcbFile) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; return RTFileGetSize(pThis->hFile, pcbFile); } /** * @interface_method_impl{RTVFSFILEOPS,pfnSetSize} */ static DECLCALLBACK(int) rtVfsStdFile_SetSize(void *pvThis, uint64_t cbFile, uint32_t fFlags) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; switch (fFlags & RTVFSFILE_SIZE_F_ACTION_MASK) { case RTVFSFILE_SIZE_F_NORMAL: return RTFileSetSize(pThis->hFile, cbFile); case RTVFSFILE_SIZE_F_GROW: return RTFileSetAllocationSize(pThis->hFile, cbFile, RTFILE_ALLOC_SIZE_F_DEFAULT); case RTVFSFILE_SIZE_F_GROW_KEEP_SIZE: return RTFileSetAllocationSize(pThis->hFile, cbFile, RTFILE_ALLOC_SIZE_F_KEEP_SIZE); default: return VERR_NOT_SUPPORTED; } } /** * @interface_method_impl{RTVFSFILEOPS,pfnQueryMaxSize} */ static DECLCALLBACK(int) rtVfsStdFile_QueryMaxSize(void *pvThis, uint64_t *pcbMax) { PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; RTFOFF cbMax = 0; int rc = RTFileGetMaxSizeEx(pThis->hFile, &cbMax); if (RT_SUCCESS(rc)) *pcbMax = cbMax; return rc; } /** * Standard file operations. */ DECL_HIDDEN_CONST(const RTVFSFILEOPS) g_rtVfsStdFileOps = { { /* Stream */ { /* Obj */ RTVFSOBJOPS_VERSION, RTVFSOBJTYPE_FILE, "StdFile", rtVfsStdFile_Close, rtVfsStdFile_QueryInfo, RTVFSOBJOPS_VERSION }, RTVFSIOSTREAMOPS_VERSION, 0, rtVfsStdFile_Read, rtVfsStdFile_Write, rtVfsStdFile_Flush, rtVfsStdFile_PollOne, rtVfsStdFile_Tell, rtVfsStdFile_Skip, NULL /*ZeroFill*/, RTVFSIOSTREAMOPS_VERSION, }, RTVFSFILEOPS_VERSION, 0, { /* ObjSet */ RTVFSOBJSETOPS_VERSION, RT_UOFFSETOF(RTVFSFILEOPS, ObjSet) - RT_UOFFSETOF(RTVFSFILEOPS, Stream.Obj), rtVfsStdFile_SetMode, rtVfsStdFile_SetTimes, rtVfsStdFile_SetOwner, RTVFSOBJSETOPS_VERSION }, rtVfsStdFile_Seek, rtVfsStdFile_QuerySize, rtVfsStdFile_SetSize, rtVfsStdFile_QueryMaxSize, RTVFSFILEOPS_VERSION }; /** * Internal worker for RTVfsFileFromRTFile and RTVfsFileOpenNormal. * * @returns IRPT status code. * @param hFile The IPRT file handle. * @param fOpen The RTFILE_O_XXX flags. * @param fLeaveOpen Whether to leave it open or close it. * @param phVfsFile Where to return the handle. */ static int rtVfsFileFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSFILE phVfsFile) { PRTVFSSTDFILE pThis; RTVFSFILE hVfsFile; int rc = RTVfsNewFile(&g_rtVfsStdFileOps, sizeof(RTVFSSTDFILE), fOpen, NIL_RTVFS, NIL_RTVFSLOCK, &hVfsFile, (void **)&pThis); if (RT_FAILURE(rc)) return rc; pThis->hFile = hFile; pThis->fLeaveOpen = fLeaveOpen; *phVfsFile = hVfsFile; return VINF_SUCCESS; } RTDECL(int) RTVfsFileFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSFILE phVfsFile) { /* * Check the handle validity. */ RTFSOBJINFO ObjInfo; int rc = RTFileQueryInfo(hFile, &ObjInfo, RTFSOBJATTRADD_NOTHING); if (RT_FAILURE(rc)) return rc; /* * Set up some fake fOpen flags if necessary and create a VFS file handle. */ if (!fOpen) fOpen = RTFILE_O_READWRITE | RTFILE_O_DENY_NONE | RTFILE_O_OPEN_CREATE; return rtVfsFileFromRTFile(hFile, fOpen, fLeaveOpen, phVfsFile); } RTDECL(int) RTVfsFileOpenNormal(const char *pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile) { /* * Open the file the normal way and pass it to RTVfsFileFromRTFile. */ RTFILE hFile; int rc = RTFileOpen(&hFile, pszFilename, fOpen); if (RT_SUCCESS(rc)) { /* * Create a VFS file handle. */ rc = rtVfsFileFromRTFile(hFile, fOpen, false /*fLeaveOpen*/, phVfsFile); if (RT_FAILURE(rc)) RTFileClose(hFile); } return rc; } RTDECL(int) RTVfsIoStrmFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSIOSTREAM phVfsIos) { RTVFSFILE hVfsFile; int rc = RTVfsFileFromRTFile(hFile, fOpen, fLeaveOpen, &hVfsFile); if (RT_SUCCESS(rc)) { *phVfsIos = RTVfsFileToIoStream(hVfsFile); RTVfsFileRelease(hVfsFile); } return rc; } RTDECL(int) RTVfsIoStrmOpenNormal(const char *pszFilename, uint64_t fOpen, PRTVFSIOSTREAM phVfsIos) { RTVFSFILE hVfsFile; int rc = RTVfsFileOpenNormal(pszFilename, fOpen, &hVfsFile); if (RT_SUCCESS(rc)) { *phVfsIos = RTVfsFileToIoStream(hVfsFile); RTVfsFileRelease(hVfsFile); } return rc; } /** * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnValidate} */ static DECLCALLBACK(int) rtVfsChainStdFile_Validate(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo) { RT_NOREF(pProviderReg); /* * Basic checks. */ if (pElement->enmTypeIn != RTVFSOBJTYPE_INVALID) return VERR_VFS_CHAIN_MUST_BE_FIRST_ELEMENT; if ( pElement->enmType != RTVFSOBJTYPE_FILE && pElement->enmType != RTVFSOBJTYPE_IO_STREAM) return VERR_VFS_CHAIN_ONLY_FILE_OR_IOS; /* * Join common cause with the 'open' provider. */ return RTVfsChainValidateOpenFileOrIoStream(pSpec, pElement, poffError, pErrInfo); } /** * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnInstantiate} */ static DECLCALLBACK(int) rtVfsChainStdFile_Instantiate(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj, PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo) { RT_NOREF(pProviderReg, pSpec, poffError, pErrInfo); AssertReturn(hPrevVfsObj == NIL_RTVFSOBJ, VERR_VFS_CHAIN_IPE); RTVFSFILE hVfsFile; int rc = RTVfsFileOpenNormal(pElement->paArgs[0].psz, pElement->uProvider, &hVfsFile); if (RT_SUCCESS(rc)) { *phVfsObj = RTVfsObjFromFile(hVfsFile); RTVfsFileRelease(hVfsFile); if (*phVfsObj != NIL_RTVFSOBJ) return VINF_SUCCESS; rc = VERR_VFS_CHAIN_CAST_FAILED; } return rc; } /** * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnCanReuseElement} */ static DECLCALLBACK(bool) rtVfsChainStdFile_CanReuseElement(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement, PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement) { RT_NOREF(pProviderReg, pSpec, pReuseSpec); if (strcmp(pElement->paArgs[0].psz, pReuseElement->paArgs[0].psz) == 0) if (pElement->paArgs[0].uProvider == pReuseElement->paArgs[0].uProvider) return true; return false; } /** VFS chain element 'file'. */ static RTVFSCHAINELEMENTREG g_rtVfsChainStdFileReg = { /* uVersion = */ RTVFSCHAINELEMENTREG_VERSION, /* fReserved = */ 0, /* pszName = */ "stdfile", /* ListEntry = */ { NULL, NULL }, /* pszHelp = */ "Open a real file, providing either a file or an I/O stream object. Initial element.\n" "First argument is the filename path.\n" "Second argument is access mode, optional: r, w, rw.\n" "Third argument is open disposition, optional: create, create-replace, open, open-create, open-append, open-truncate.\n" "Forth argument is file sharing, optional: nr, nw, nrw, d.", /* pfnValidate = */ rtVfsChainStdFile_Validate, /* pfnInstantiate = */ rtVfsChainStdFile_Instantiate, /* pfnCanReuseElement = */ rtVfsChainStdFile_CanReuseElement, /* uEndMarker = */ RTVFSCHAINELEMENTREG_VERSION }; RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(&g_rtVfsChainStdFileReg, rtVfsChainStdFileReg);