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Diffstat (limited to '')
| -rw-r--r-- | src/VBox/Runtime/r3/win/pathint-win.cpp | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/win/pathint-win.cpp b/src/VBox/Runtime/r3/win/pathint-win.cpp new file mode 100644 index 00000000..dff349ea --- /dev/null +++ b/src/VBox/Runtime/r3/win/pathint-win.cpp @@ -0,0 +1,194 @@ +/* $Id: pathint-win.cpp $ */ +/** @file + * IPRT - Windows, Internal Path stuff. + */ + +/* + * Copyright (C) 2006-2019 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 * +*********************************************************************************************************************************/ +#define LOG_GROUP RTLOGGROUP_FS +#include <iprt/path.h> + +#include <iprt/assert.h> +#include <iprt/ctype.h> +#include <iprt/errcore.h> +#include <iprt/string.h> +#include <iprt/utf16.h> + +#include <iprt/nt/nt-and-windows.h> + + +/********************************************************************************************************************************* +* Defined Constants And Macros * +*********************************************************************************************************************************/ +/** The max number of non-null characters we pass to an Win32 API. + * You would think that MAX_PATH gives this length, however CreateDirectoryW was + * found to fail on Windows 10 (1803++) if given a perfectly formed path argument + * of 248 or more characters. Same when going thru UNC. + * + * So, to be conservative, we put the max number of characters in a non-\\?\ + * path to 243, not counting the terminator. + */ +#define ACTUAL_MAX_PATH 243 + + +DECL_NO_INLINE(static, bool) rtPathWinTryConvertToAbs(PRTUTF16 *ppwszPath) +{ + RTUTF16 wszFullPath[MAX_PATH + 1]; + DWORD cwcFull = GetFullPathNameW(*ppwszPath, MAX_PATH + 1, wszFullPath, NULL); + if (cwcFull <= ACTUAL_MAX_PATH) + { + RTUtf16Free(*ppwszPath); + PRTUTF16 const pwszCopy = RTUtf16Dup(wszFullPath); + *ppwszPath = pwszCopy; + if (pwszCopy) + return true; + } + return false; +} + + +RTDECL(int) RTPathWinFromUtf8(PRTUTF16 *ppwszPath, const char *pszPath, uint32_t fFlags) +{ + Assert(fFlags == 0); + RT_NOREF(fFlags); + + /* + * Do a straight conversion first. + */ + *ppwszPath = NULL; + size_t cwcResult = 0; + int rc = RTStrToUtf16Ex(pszPath, RTSTR_MAX, ppwszPath, 0, &cwcResult); + if (RT_SUCCESS(rc)) + { + /* + * Check the resulting length. This is straight forward for absolute + * paths, but gets complicated for relative ones. + */ + if (cwcResult <= ACTUAL_MAX_PATH) + { + if (RT_C_IS_ALPHA(pszPath[0]) && pszPath[1] == ':') + { + if (RTPATH_IS_SLASH(pszPath[2])) + return VINF_SUCCESS; + + /* Drive relative path. Found no simple way of getting the current + path of a drive, so we try convert it to an absolute path and see + how that works out. It is what the API we're calling will have to + do anyway, so this should perform just as well. */ + if (rtPathWinTryConvertToAbs(ppwszPath)) + return VINF_SUCCESS; + } + else if (RTPATH_IS_SLASH(pszPath[0])) + { + if ( RTPATH_IS_SLASH(pszPath[1]) + && !RTPATH_IS_SLASH(pszPath[2]) + && pszPath[2] != '\0') + { + /* Passthru prefix '\\?\' is fine. */ + if ( pszPath[2] == '?' + && !RTPATH_IS_SLASH(pszPath[3])) + return VINF_SUCCESS; + + /* UNC requires a longer prefix ('\??\UNC\' instead of '\??\'), so + subtract 3 chars from the max limit to be on the safe side. */ + if (cwcResult <= ACTUAL_MAX_PATH - 3) + return VINF_SUCCESS; + } + else + { + /* Drive relative. Win32 will prepend a two letter drive specification. */ + if (cwcResult <= ACTUAL_MAX_PATH - 2) + return VINF_SUCCESS; + } + } + else + { + /* Relative to CWD. We can use the API to get it's current length. + Any race conditions here is entirely the caller's problem. */ + size_t cwcCwd = GetCurrentDirectoryW(0, NULL); + if (cwcCwd + cwcResult <= ACTUAL_MAX_PATH - 1) + return VINF_SUCCESS; + } + } + /* + * We're good if the caller already supplied the passthru/length prefix: '\\?\' + */ + else if ( pszPath[1] == '?' + && RTPATH_IS_SLASH(pszPath[3]) + && RTPATH_IS_SLASH(pszPath[1]) + && RTPATH_IS_SLASH(pszPath[0])) + return VINF_SUCCESS; + + /* + * Long path requiring \\?\ prefixing. + * + * We piggy back on the NT conversion here and ASSUME RTUtf16Free is the right + * way to free the result. + */ + RTUtf16Free(*ppwszPath); + *ppwszPath = NULL; + + struct _UNICODE_STRING NtName = { 0, 0, NULL }; + HANDLE hRootDir = NULL; + rc = RTNtPathFromWinUtf8(&NtName, &hRootDir, pszPath); + if (RT_SUCCESS(rc)) + { + /* No root dir handle. */ + if (hRootDir == NULL) + { + /* Convert the NT '\??\' prefix to a win32 passthru prefix '\\?\' */ + if ( NtName.Buffer[0] == '\\' + && NtName.Buffer[1] == '?' + && NtName.Buffer[2] == '?' + && NtName.Buffer[3] == '\\') + { + NtName.Buffer[1] = '\\'; + + /* Zero termination paranoia. */ + if (NtName.Buffer[NtName.Length / sizeof(RTUTF16)] == '\0') + { + *ppwszPath = NtName.Buffer; + return VINF_SUCCESS; + } + AssertMsgFailed(("Length=%u %.*ls\n", NtName.Length, NtName.Length / sizeof(RTUTF16), NtName.Buffer)); + } + else + AssertMsgFailed(("%ls\n", NtName.Buffer)); + } + else + AssertMsgFailed(("%s\n", pszPath)); + RTNtPathFree(&NtName, &hRootDir); + } + } + return rc; +} + + +RTDECL(void) RTPathWinFree(PRTUTF16 pwszPath) +{ + RTUtf16Free(pwszPath); +} + |