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Diffstat (limited to '')
| -rw-r--r-- | src/VBox/Runtime/r3/win/symlink-win.cpp | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/win/symlink-win.cpp b/src/VBox/Runtime/r3/win/symlink-win.cpp new file mode 100644 index 00000000..8da5cea3 --- /dev/null +++ b/src/VBox/Runtime/r3/win/symlink-win.cpp @@ -0,0 +1,357 @@ +/* $Id: symlink-win.cpp $ */ +/** @file + * IPRT - Symbolic Links, Windows. + */ + +/* + * Copyright (C) 2010-2020 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 * +*********************************************************************************************************************************/ +#define LOG_GROUP RTLOGGROUP_SYMLINK +#include <iprt/win/windows.h> + +#include <iprt/symlink.h> +#include "internal-r3-win.h" + +#include <iprt/assert.h> +#include <iprt/err.h> +#include <iprt/log.h> +#include <iprt/path.h> +#include <iprt/mem.h> +#include <iprt/string.h> +#include <iprt/utf16.h> +#include "internal/path.h" + + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +typedef struct MY_REPARSE_DATA_BUFFER +{ + ULONG ReparseTag; +#define MY_IO_REPARSE_TAG_SYMLINK 0xa000000c +#define MY_IO_REPARSE_TAG_MOUNT_POINT 0xa0000003 + + USHORT ReparseDataLength; + USHORT Reserved; + union + { + struct + { + USHORT SubstituteNameOffset; + USHORT SubstituteNameLength; + USHORT PrintNameOffset; + USHORT PrintNameLength; + ULONG Flags; +#define MY_SYMLINK_FLAG_RELATIVE 1 + WCHAR PathBuffer[1]; + } SymbolicLinkReparseBuffer; + struct + { + USHORT SubstituteNameOffset; + USHORT SubstituteNameLength; + USHORT PrintNameOffset; + USHORT PrintNameLength; + WCHAR PathBuffer[1]; + } MountPointReparseBuffer; + struct + { + UCHAR DataBuffer[1]; + } GenericReparseBuffer; + }; +} MY_REPARSE_DATA_BUFFER; +#define MY_FSCTL_GET_REPARSE_POINT CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 42, METHOD_BUFFERED, FILE_ANY_ACCESS) + + +RTDECL(bool) RTSymlinkExists(const char *pszSymlink) +{ + bool fRc = false; + RTFSOBJINFO ObjInfo; + int rc = RTPathQueryInfoEx(pszSymlink, &ObjInfo, RTFSOBJATTRADD_NOTHING, RTPATH_F_ON_LINK); + if (RT_SUCCESS(rc)) + fRc = RTFS_IS_SYMLINK(ObjInfo.Attr.fMode); + + LogFlow(("RTSymlinkExists(%p={%s}): returns %RTbool\n", pszSymlink, pszSymlink, fRc)); + return fRc; +} + + +RTDECL(bool) RTSymlinkIsDangling(const char *pszSymlink) +{ + bool fRc = false; + RTFSOBJINFO ObjInfo; + int rc = RTPathQueryInfoEx(pszSymlink, &ObjInfo, RTFSOBJATTRADD_NOTHING, RTPATH_F_ON_LINK); + if (RT_SUCCESS(rc)) + { + fRc = RTFS_IS_SYMLINK(ObjInfo.Attr.fMode); + if (fRc) + { + rc = RTPathQueryInfoEx(pszSymlink, &ObjInfo, RTFSOBJATTRADD_NOTHING, RTPATH_F_FOLLOW_LINK); + fRc = !RT_SUCCESS_NP(rc); + } + } + + LogFlow(("RTSymlinkIsDangling(%p={%s}): returns %RTbool\n", pszSymlink, pszSymlink, fRc)); + return fRc; +} + + +RTDECL(int) RTSymlinkCreate(const char *pszSymlink, const char *pszTarget, RTSYMLINKTYPE enmType, uint32_t fCreate) +{ + /* + * Validate the input. + */ + AssertReturn(enmType > RTSYMLINKTYPE_INVALID && enmType < RTSYMLINKTYPE_END, VERR_INVALID_PARAMETER); + AssertPtrReturn(pszSymlink, VERR_INVALID_POINTER); + AssertPtrReturn(pszTarget, VERR_INVALID_POINTER); + RT_NOREF_PV(fCreate); + + /* + * Resolve the API. + */ + typedef BOOLEAN (WINAPI *PFNCREATESYMBOLICLINKW)(LPCWSTR, LPCWSTR, DWORD); + static PFNCREATESYMBOLICLINKW s_pfnCreateSymbolicLinkW = NULL; + static bool s_fTried = FALSE; + if (!s_fTried) + { + PFNCREATESYMBOLICLINKW pfn = (PFNCREATESYMBOLICLINKW)GetProcAddress(g_hModKernel32, "CreateSymbolicLinkW"); + if (pfn) + s_pfnCreateSymbolicLinkW = pfn; + s_fTried = true; + } + if (!s_pfnCreateSymbolicLinkW) + { + LogFlow(("RTSymlinkCreate(%p={%s}, %p={%s}, %d, %#x): returns VERR_NOT_SUPPORTED - Windows API not found\n", + pszSymlink, pszSymlink, pszTarget, pszTarget, enmType, fCreate)); + return VERR_NOT_SUPPORTED; + } + + /* + * Convert the paths. + */ + PRTUTF16 pwszNativeSymlink; + int rc = RTPathWinFromUtf8(&pwszNativeSymlink, pszSymlink, 0 /*fFlags*/); + if (RT_SUCCESS(rc)) + { + PRTUTF16 pwszNativeTarget; + rc = RTPathWinFromUtf8(&pwszNativeTarget, pszTarget, 0 /*fFlags*/); + if (RT_SUCCESS(rc)) + { + /* The link target path must use backslashes to work reliably. */ + RTUTF16 wc; + PRTUTF16 pwsz = pwszNativeTarget; + while ((wc = *pwsz) != '\0') + { + if (wc == '/') + *pwsz = '\\'; + pwsz++; + } + + /* + * Massage the target path, determin the link type. + */ + size_t cchTarget = strlen(pszTarget); + size_t cchVolSpecTarget = rtPathVolumeSpecLen(pszTarget); +#if 0 /* looks like this isn't needed after all. That makes everything much simper :-) */ + if ( cchTarget > RT_MIN(cchVolSpecTarget, 1) + && RTPATH_IS_SLASH(pszTarget[cchTarget - 1])) + { + size_t cwcNativeTarget = RTUtf16Len(pwszNativeTarget); + size_t offFromEnd = 1; + while ( offFromEnd < cchTarget + && cchTarget - offFromEnd >= cchVolSpecTarget + && RTPATH_IS_SLASH(pszTarget[cchTarget - offFromEnd])) + { + Assert(offFromEnd < cwcNativeTarget); + pwszNativeTarget[cwcNativeTarget - offFromEnd] = 0; + offFromEnd++; + } + } +#endif + + if (enmType == RTSYMLINKTYPE_UNKNOWN) + { + if ( cchTarget > cchVolSpecTarget + && RTPATH_IS_SLASH(pszTarget[cchTarget - 1])) + enmType = RTSYMLINKTYPE_DIR; + else if (cchVolSpecTarget) + { + /** @todo this is subject to sharing violations. */ + DWORD dwAttr = GetFileAttributesW(pwszNativeTarget); + if ( dwAttr != INVALID_FILE_ATTRIBUTES + && (dwAttr & FILE_ATTRIBUTE_DIRECTORY)) + enmType = RTSYMLINKTYPE_DIR; + } + else + { + /** @todo Join the symlink directory with the target and + * look up the attributes on that. -lazy bird. */ + } + } + + /* + * Create the link. + */ + if (s_pfnCreateSymbolicLinkW(pwszNativeSymlink, pwszNativeTarget, enmType == RTSYMLINKTYPE_DIR)) + rc = VINF_SUCCESS; + else + rc = RTErrConvertFromWin32(GetLastError()); + + RTPathWinFree(pwszNativeTarget); + } + RTPathWinFree(pwszNativeSymlink); + } + + LogFlow(("RTSymlinkCreate(%p={%s}, %p={%s}, %d, %#x): returns %Rrc\n", pszSymlink, pszSymlink, pszTarget, pszTarget, enmType, fCreate, rc)); + return rc; +} + + +RTDECL(int) RTSymlinkDelete(const char *pszSymlink, uint32_t fDelete) +{ + RT_NOREF_PV(fDelete); + + /* + * Convert the path. + */ + PRTUTF16 pwszNativeSymlink; + int rc = RTPathWinFromUtf8(&pwszNativeSymlink, pszSymlink, 0 /*fFlags*/); + if (RT_SUCCESS(rc)) + { + /* + * We have to use different APIs depending on whether this is a + * directory or file link. This means we're subject to one more race + * than on posix at the moment. We could probably avoid this though, + * if we wanted to go talk with the native API layer below Win32... + */ + DWORD dwAttr = GetFileAttributesW(pwszNativeSymlink); + if (dwAttr != INVALID_FILE_ATTRIBUTES) + { + if (dwAttr & FILE_ATTRIBUTE_REPARSE_POINT) + { + BOOL fRc; + if (dwAttr & FILE_ATTRIBUTE_DIRECTORY) + fRc = RemoveDirectoryW(pwszNativeSymlink); + else + fRc = DeleteFileW(pwszNativeSymlink); + if (fRc) + rc = VINF_SUCCESS; + else + rc = RTErrConvertFromWin32(GetLastError()); + } + else + rc = VERR_NOT_SYMLINK; + } + else + rc = RTErrConvertFromWin32(GetLastError()); + RTPathWinFree(pwszNativeSymlink); + } + + LogFlow(("RTSymlinkDelete(%p={%s}, %#x): returns %Rrc\n", pszSymlink, pszSymlink, fDelete, rc)); + return rc; +} + + +RTDECL(int) RTSymlinkRead(const char *pszSymlink, char *pszTarget, size_t cbTarget, uint32_t fRead) +{ + RT_NOREF_PV(fRead); + + char *pszMyTarget; + int rc = RTSymlinkReadA(pszSymlink, &pszMyTarget); + if (RT_SUCCESS(rc)) + { + rc = RTStrCopy(pszTarget, cbTarget, pszMyTarget); + RTStrFree(pszMyTarget); + } + LogFlow(("RTSymlinkRead(%p={%s}): returns %Rrc\n", pszSymlink, pszSymlink, rc)); + return rc; +} + + +RTDECL(int) RTSymlinkReadA(const char *pszSymlink, char **ppszTarget) +{ + AssertPtr(ppszTarget); + PRTUTF16 pwszNativeSymlink; + int rc = RTPathWinFromUtf8(&pwszNativeSymlink, pszSymlink, 0 /*fFlags*/); + if (RT_SUCCESS(rc)) + { + HANDLE hSymlink = CreateFileW(pwszNativeSymlink, + GENERIC_READ, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, + NULL, + OPEN_EXISTING, + FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, + NULL); + if (hSymlink != INVALID_HANDLE_VALUE) + { + DWORD cbReturned = 0; + union + { + MY_REPARSE_DATA_BUFFER Buf; + uint8_t abBuf[16*_1K + sizeof(WCHAR)]; + } u; + if (DeviceIoControl(hSymlink, + MY_FSCTL_GET_REPARSE_POINT, + NULL /*pInBuffer */, + 0 /*cbInBuffer */, + &u.Buf, + sizeof(u) - sizeof(WCHAR), + &cbReturned, + NULL /*pOverlapped*/)) + { + if (u.Buf.ReparseTag == MY_IO_REPARSE_TAG_SYMLINK) + { + PWCHAR pwszTarget = &u.Buf.SymbolicLinkReparseBuffer.PathBuffer[0]; + pwszTarget += u.Buf.SymbolicLinkReparseBuffer.SubstituteNameOffset / 2; + pwszTarget[u.Buf.SymbolicLinkReparseBuffer.SubstituteNameLength / 2] = 0; + if ( !(u.Buf.SymbolicLinkReparseBuffer.Flags & MY_SYMLINK_FLAG_RELATIVE) + && pwszTarget[0] == '\\' + && pwszTarget[1] == '?' + && pwszTarget[2] == '?' + && pwszTarget[3] == '\\' + && pwszTarget[4] != 0 + ) + pwszTarget += 4; + rc = RTUtf16ToUtf8(pwszTarget, ppszTarget); + } + else + rc = VERR_NOT_SYMLINK; + } + else + rc = RTErrConvertFromWin32(GetLastError()); + CloseHandle(hSymlink); + } + else + rc = RTErrConvertFromWin32(GetLastError()); + RTPathWinFree(pwszNativeSymlink); + } + + if (RT_SUCCESS(rc)) + LogFlow(("RTSymlinkReadA(%p={%s},%p): returns %Rrc *ppszTarget=%p:{%s}\n", pszSymlink, pszSymlink, ppszTarget, rc, *ppszTarget, *ppszTarget)); + else + LogFlow(("RTSymlinkReadA(%p={%s},%p): returns %Rrc\n", pszSymlink, pszSymlink, ppszTarget, rc)); + return rc; +} + |