vfschain.cpp@ 74525

Last change on this file since 74525 was 70997, checked in by vboxsync, 7 years ago
RTVfsChainOpenDir: Default to READ access.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 64.1 KB

Line
1	/* $Id: vfschain.cpp 70997 2018-02-13 12:42:11Z vboxsync $ */
2	/** @file
3	* IPRT - Virtual File System, Chains.
4	*/
5
6	/*
7	* Copyright (C) 2010-2017 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*********************************************************************************************************************************
29	* Header Files *
30	*********************************************************************************************************************************/
31	#include <iprt/vfs.h>
32	#include <iprt/vfslowlevel.h>
33
34	#include <iprt/asm.h>
35	#include <iprt/critsect.h>
36	#include <iprt/ctype.h>
37	#include <iprt/err.h>
38	#include <iprt/file.h>
39	#include <iprt/mem.h>
40	#include <iprt/once.h>
41	#include <iprt/param.h>
42	#include <iprt/path.h>
43	#include <iprt/semaphore.h>
44	#include <iprt/string.h>
45
46	#include "internal/file.h"
47	#include "internal/magics.h"
48	//#include "internal/vfs.h"
49
50
51	/*********************************************************************************************************************************
52	* Internal Functions *
53	*********************************************************************************************************************************/
54	static PCRTVFSCHAINELEMENTREG rtVfsChainFindProviderLocked(const char *pszProvider);
55
56
57	/*********************************************************************************************************************************
58	* Global Variables *
59	*********************************************************************************************************************************/
60	/** Init the critical section once. */
61	static RTONCE g_rtVfsChainElementInitOnce = RTONCE_INITIALIZER;
62	/** Critical section protecting g_rtVfsChainElementProviderList. */
63	static RTCRITSECTRW g_rtVfsChainElementCritSect;
64	/** List of VFS chain element providers (RTVFSCHAINELEMENTREG). */
65	static RTLISTANCHOR g_rtVfsChainElementProviderList;
66
67
68
69	RTDECL(int) RTVfsChainValidateOpenFileOrIoStream(PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement,
70	uint32_t *poffError, PRTERRINFO pErrInfo)
71	{
72	if (pElement->cArgs < 1)
73	return VERR_VFS_CHAIN_AT_LEAST_ONE_ARG;
74	if (pElement->cArgs > 4)
75	return VERR_VFS_CHAIN_AT_MOST_FOUR_ARGS;
76	if (!*pElement->paArgs[0].psz)
77	return VERR_VFS_CHAIN_EMPTY_ARG;
78
79	/*
80	* Calculate the flags, storing them in the first argument.
81	*/
82	const char *pszAccess = pElement->cArgs >= 2 ? pElement->paArgs[1].psz : "";
83	if (!*pszAccess)
84	pszAccess = (pSpec->fOpenFile & RTFILE_O_ACCESS_MASK) == RTFILE_O_READWRITE ? "rw"
85	: (pSpec->fOpenFile & RTFILE_O_ACCESS_MASK) == RTFILE_O_READ ? "r"
86	: (pSpec->fOpenFile & RTFILE_O_ACCESS_MASK) == RTFILE_O_WRITE ? "w"
87	: "rw";
88
89	const char *pszDisp = pElement->cArgs >= 3 ? pElement->paArgs[2].psz : "";
90	if (!*pszDisp)
91	pszDisp = strchr(pszAccess, 'w') != NULL ? "open-create" : "open";
92
93	const char *pszSharing = pElement->cArgs >= 4 ? pElement->paArgs[3].psz : "";
94
95	int rc = RTFileModeToFlagsEx(pszAccess, pszDisp, pszSharing, &pElement->uProvider);
96	if (RT_SUCCESS(rc))
97	return VINF_SUCCESS;
98
99	/*
100	* Now try figure out which argument offended us.
101	*/
102	AssertReturn(pElement->cArgs > 1, VERR_VFS_CHAIN_IPE);
103	if ( pElement->cArgs == 2
104	\|\| RT_FAILURE(RTFileModeToFlagsEx(pszAccess, "open-create", "", &pElement->uProvider)))
105	{
106	*poffError = pElement->paArgs[1].offSpec;
107	rc = RTErrInfoSet(pErrInfo, VERR_VFS_CHAIN_INVALID_ARGUMENT, "Expected valid access flags: 'r', 'rw', or 'w'");
108	}
109	else if ( pElement->cArgs == 3
110	\|\| RT_FAILURE(RTFileModeToFlagsEx(pszAccess, pszDisp, "", &pElement->uProvider)))
111	{
112	*poffError = pElement->paArgs[2].offSpec;
113	rc = RTErrInfoSet(pErrInfo, VERR_VFS_CHAIN_INVALID_ARGUMENT,
114	"Expected valid open disposition: create, create-replace, open, open-create, open-append, open-truncate");
115	}
116	else
117	{
118	*poffError = pElement->paArgs[3].offSpec;
119	rc = RTErrInfoSet(pErrInfo, VERR_VFS_CHAIN_INVALID_ARGUMENT, "Expected valid sharing flags: nr, nw, nrw, d");
120
121	}
122	return rc;
123	}
124
125
126	/**
127	* @interface_method_impl{RTVFSCHAINELEMENTREG,pfnValidate}
128	*/
129	static DECLCALLBACK(int) rtVfsChainOpen_Validate(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
130	PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo)
131	{
132	RT_NOREF(pProviderReg);
133
134	/*
135	* Basic checks.
136	*/
137	if ( pElement->enmType != RTVFSOBJTYPE_DIR
138	&& pElement->enmType != RTVFSOBJTYPE_FILE
139	&& pElement->enmType != RTVFSOBJTYPE_IO_STREAM)
140	return VERR_VFS_CHAIN_ONLY_FILE_OR_IOS_OR_DIR;
141	if ( pElement->enmTypeIn != RTVFSOBJTYPE_DIR
142	&& pElement->enmTypeIn != RTVFSOBJTYPE_FS_STREAM
143	&& pElement->enmTypeIn != RTVFSOBJTYPE_VFS)
144	{
145	if (pElement->enmTypeIn == RTVFSOBJTYPE_INVALID)
146	{
147	/*
148	* First element: Transform into 'stdfile' or 'stddir' if registered.
149	*/
150	const char *pszNewProvider = pElement->enmType == RTVFSOBJTYPE_DIR ? "stddir" : "stdfile";
151	PCRTVFSCHAINELEMENTREG pNewProvider = rtVfsChainFindProviderLocked(pszNewProvider);
152	if (pNewProvider)
153	{
154	pElement->pProvider = pNewProvider;
155	return pNewProvider->pfnValidate(pNewProvider, pSpec, pElement, poffError, pErrInfo);
156	}
157	return VERR_VFS_CHAIN_CANNOT_BE_FIRST_ELEMENT;
158	}
159	return VERR_VFS_CHAIN_TAKES_DIR_OR_FSS_OR_VFS;
160	}
161
162	/*
163	* Make common cause with 'stdfile' if we're opening a file or I/O stream.
164	* If the input is a FSS, we have to make sure it's a read-only operation.
165	*/
166	if ( pElement->enmType == RTVFSOBJTYPE_FILE
167	\|\| pElement->enmType == RTVFSOBJTYPE_IO_STREAM)
168	{
169	int rc = RTVfsChainValidateOpenFileOrIoStream(pSpec, pElement, poffError, pErrInfo);
170	if (RT_SUCCESS(rc))
171	{
172	if (pElement->enmTypeIn != RTVFSOBJTYPE_FS_STREAM)
173	return VINF_SUCCESS;
174	if ( !(pElement->uProvider & RTFILE_O_WRITE)
175	&& (pElement->uProvider & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN)
176	return VINF_SUCCESS;
177	*poffError = pElement->cArgs > 1 ? pElement->paArgs[1].offSpec : pElement->offSpec;
178	return VERR_VFS_CHAIN_INVALID_ARGUMENT;
179	}
180	return rc;
181	}
182
183
184	/*
185	* Directory checks. Path argument only, optional. If not given the root directory of a VFS or the
186	*/
187	if (pElement->cArgs > 1)
188	return VERR_VFS_CHAIN_AT_MOST_ONE_ARG;
189	pElement->uProvider = 0;
190	return VINF_SUCCESS;
191	}
192
193
194	/**
195	* @interface_method_impl{RTVFSCHAINELEMENTREG,pfnInstantiate}
196	*/
197	static DECLCALLBACK(int) rtVfsChainOpen_Instantiate(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
198	PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
199	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo)
200	{
201	RT_NOREF(pProviderReg, pSpec, pElement, poffError, pErrInfo);
202	AssertReturn(hPrevVfsObj != NIL_RTVFSOBJ, VERR_VFS_CHAIN_IPE);
203
204	/*
205	* File system stream: Seek thru the stream looking for the object to open.
206	*/
207	RTVFSFSSTREAM hVfsFssIn = RTVfsObjToFsStream(hPrevVfsObj);
208	if (hVfsFssIn != NIL_RTVFSFSSTREAM)
209	{
210	return VERR_NOT_IMPLEMENTED;
211	}
212
213	/*
214	* VFS: Use RTVfsFileOpen or RTVfsDirOpen.
215	*/
216	RTVFS hVfsIn = RTVfsObjToVfs(hPrevVfsObj);
217	if (hVfsIn != NIL_RTVFS)
218	{
219	if ( pElement->enmType == RTVFSOBJTYPE_FILE
220	\|\| pElement->enmType == RTVFSOBJTYPE_IO_STREAM)
221	{
222	RTVFSFILE hVfsFile = NIL_RTVFSFILE;
223	int rc = RTVfsFileOpen(hVfsIn, pElement->paArgs[0].psz, pElement->uProvider, &hVfsFile);
224	RTVfsRelease(hVfsIn);
225	if (RT_SUCCESS(rc))
226	{
227	*phVfsObj = RTVfsObjFromFile(hVfsFile);
228	RTVfsFileRelease(hVfsFile);
229	if (*phVfsObj != NIL_RTVFSOBJ)
230	return VINF_SUCCESS;
231	rc = VERR_VFS_CHAIN_CAST_FAILED;
232	}
233	return rc;
234	}
235	if (pElement->enmType == RTVFSOBJTYPE_DIR)
236	{
237	RTVFSDIR hVfsDir = NIL_RTVFSDIR;
238	int rc = RTVfsDirOpen(hVfsIn, pElement->paArgs[0].psz, (uint32_t)pElement->uProvider, &hVfsDir);
239	RTVfsRelease(hVfsIn);
240	if (RT_SUCCESS(rc))
241	{
242	*phVfsObj = RTVfsObjFromDir(hVfsDir);
243	RTVfsDirRelease(hVfsDir);
244	if (*phVfsObj != NIL_RTVFSOBJ)
245	return VINF_SUCCESS;
246	rc = VERR_VFS_CHAIN_CAST_FAILED;
247	}
248	return rc;
249	}
250	RTVfsRelease(hVfsIn);
251	return VERR_VFS_CHAIN_IPE;
252	}
253
254	/*
255	* Directory: Similar to above, just relative to a directory.
256	*/
257	RTVFSDIR hVfsDirIn = RTVfsObjToDir(hPrevVfsObj);
258	if (hVfsDirIn != NIL_RTVFSDIR)
259	{
260	if ( pElement->enmType == RTVFSOBJTYPE_FILE
261	\|\| pElement->enmType == RTVFSOBJTYPE_IO_STREAM)
262	{
263	RTVFSFILE hVfsFile = NIL_RTVFSFILE;
264	int rc = RTVfsDirOpenFile(hVfsDirIn, pElement->paArgs[0].psz, pElement->uProvider, &hVfsFile);
265	RTVfsDirRelease(hVfsDirIn);
266	if (RT_SUCCESS(rc))
267	{
268	*phVfsObj = RTVfsObjFromFile(hVfsFile);
269	RTVfsFileRelease(hVfsFile);
270	if (*phVfsObj != NIL_RTVFSOBJ)
271	return VINF_SUCCESS;
272	rc = VERR_VFS_CHAIN_CAST_FAILED;
273	}
274	return rc;
275	}
276	if (pElement->enmType == RTVFSOBJTYPE_DIR)
277	{
278	RTVFSDIR hVfsDir = NIL_RTVFSDIR;
279	int rc = RTVfsDirOpenDir(hVfsDirIn, pElement->paArgs[0].psz, pElement->uProvider, &hVfsDir);
280	RTVfsDirRelease(hVfsDirIn);
281	if (RT_SUCCESS(rc))
282	{
283	*phVfsObj = RTVfsObjFromDir(hVfsDir);
284	RTVfsDirRelease(hVfsDir);
285	if (*phVfsObj != NIL_RTVFSOBJ)
286	return VINF_SUCCESS;
287	rc = VERR_VFS_CHAIN_CAST_FAILED;
288	}
289	return rc;
290	}
291	RTVfsDirRelease(hVfsDirIn);
292	return VERR_VFS_CHAIN_IPE;
293	}
294
295	AssertFailed();
296	return VERR_VFS_CHAIN_CAST_FAILED;
297	}
298
299
300	/**
301	* @interface_method_impl{RTVFSCHAINELEMENTREG,pfnCanReuseElement}
302	*/
303	static DECLCALLBACK(bool) rtVfsChainOpen_CanReuseElement(PCRTVFSCHAINELEMENTREG pProviderReg,
304	PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
305	PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement)
306	{
307	RT_NOREF(pProviderReg, pSpec, pElement, pReuseSpec, pReuseElement);
308	return false;
309	}
310
311
312	/** VFS chain element 'gunzip'. */
313	static RTVFSCHAINELEMENTREG g_rtVfsChainGunzipReg =
314	{
315	/* uVersion = */ RTVFSCHAINELEMENTREG_VERSION,
316	/* fReserved = */ 0,
317	/* pszName = */ "open",
318	/* ListEntry = */ { NULL, NULL },
319	/* pszHelp = */ "Generic VFS open, that can open files (or I/O stream) and directories in a VFS, directory or file system stream.\n"
320	"If used as the first element in a chain, it will work like 'stdfile' or 'stddir' and work on the real file system.\n"
321	"First argument is the filename or directory path.\n"
322	"Second argument is access mode, files only, optional: r, w, rw.\n"
323	"Third argument is open disposition, files only, optional: create, create-replace, open, open-create, open-append, open-truncate.\n"
324	"Forth argument is file sharing, files only, optional: nr, nw, nrw, d.",
325	/* pfnValidate = */ rtVfsChainOpen_Validate,
326	/* pfnInstantiate = */ rtVfsChainOpen_Instantiate,
327	/* pfnCanReuseElement = */ rtVfsChainOpen_CanReuseElement,
328	/* uEndMarker = */ RTVFSCHAINELEMENTREG_VERSION
329	};
330
331	RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(&g_rtVfsChainGunzipReg, rtVfsChainGunzipReg);
332
333
334
335
336	/**
337	* Initializes the globals via RTOnce.
338	*
339	* @returns IPRT status code
340	* @param pvUser Unused, ignored.
341	*/
342	static DECLCALLBACK(int) rtVfsChainElementRegisterInit(void *pvUser)
343	{
344	NOREF(pvUser);
345	if (!g_rtVfsChainElementProviderList.pNext)
346	RTListInit(&g_rtVfsChainElementProviderList);
347	int rc = RTCritSectRwInit(&g_rtVfsChainElementCritSect);
348	if (RT_SUCCESS(rc))
349	{
350	}
351	return rc;
352	}
353
354
355	RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor)
356	{
357	int rc;
358
359	/*
360	* Input validation.
361	*/
362	AssertPtrReturn(pRegRec, VERR_INVALID_POINTER);
363	AssertMsgReturn(pRegRec->uVersion == RTVFSCHAINELEMENTREG_VERSION, ("%#x", pRegRec->uVersion), VERR_INVALID_POINTER);
364	AssertMsgReturn(pRegRec->uEndMarker == RTVFSCHAINELEMENTREG_VERSION, ("%#zx", pRegRec->uEndMarker), VERR_INVALID_POINTER);
365	AssertReturn(pRegRec->fReserved == 0, VERR_INVALID_POINTER);
366	AssertPtrReturn(pRegRec->pszName, VERR_INVALID_POINTER);
367	AssertPtrReturn(pRegRec->pfnValidate, VERR_INVALID_POINTER);
368	AssertPtrReturn(pRegRec->pfnInstantiate, VERR_INVALID_POINTER);
369	AssertPtrReturn(pRegRec->pfnCanReuseElement, VERR_INVALID_POINTER);
370
371	/*
372	* Init and take the lock.
373	*/
374	if (!fFromCtor)
375	{
376	rc = RTOnce(&g_rtVfsChainElementInitOnce, rtVfsChainElementRegisterInit, NULL);
377	if (RT_FAILURE(rc))
378	return rc;
379	rc = RTCritSectRwEnterExcl(&g_rtVfsChainElementCritSect);
380	if (RT_FAILURE(rc))
381	return rc;
382	}
383	else if (!g_rtVfsChainElementProviderList.pNext)
384	RTListInit(&g_rtVfsChainElementProviderList);
385
386	/*
387	* Duplicate name?
388	*/
389	rc = VINF_SUCCESS;
390	PRTVFSCHAINELEMENTREG pIterator, pIterNext;
391	RTListForEachSafe(&g_rtVfsChainElementProviderList, pIterator, pIterNext, RTVFSCHAINELEMENTREG, ListEntry)
392	{
393	if (!strcmp(pIterator->pszName, pRegRec->pszName))
394	{
395	AssertMsgFailed(("duplicate name '%s' old=%p new=%p\n", pIterator->pszName, pIterator, pRegRec));
396	rc = VERR_ALREADY_EXISTS;
397	break;
398	}
399	}
400
401	/*
402	* If not, append the record to the list.
403	*/
404	if (RT_SUCCESS(rc))
405	RTListAppend(&g_rtVfsChainElementProviderList, &pRegRec->ListEntry);
406
407	/*
408	* Leave the lock and return.
409	*/
410	if (!fFromCtor)
411	RTCritSectRwLeaveExcl(&g_rtVfsChainElementCritSect);
412	return rc;
413	}
414
415
416	/**
417	* Allocates and initializes an empty spec
418	*
419	* @returns Pointer to the spec on success, NULL on failure.
420	*/
421	static PRTVFSCHAINSPEC rtVfsChainSpecAlloc(void)
422	{
423	PRTVFSCHAINSPEC pSpec = (PRTVFSCHAINSPEC)RTMemTmpAlloc(sizeof(*pSpec));
424	if (pSpec)
425	{
426	pSpec->fOpenFile = 0;
427	pSpec->fOpenDir = 0;
428	pSpec->cElements = 0;
429	pSpec->paElements = NULL;
430	}
431	return pSpec;
432	}
433
434
435	/**
436	* Checks if @a ch is a character that can be escaped.
437	*
438	* @returns true / false.
439	* @param ch The character to consider.
440	*/
441	DECLINLINE(bool) rtVfsChainSpecIsEscapableChar(char ch)
442	{
443	return ch == '('
444	\|\| ch == ')'
445	\|\| ch == '{'
446	\|\| ch == '}'
447	\|\| ch == '\\'
448	\|\| ch == ','
449	\|\| ch == '\|'
450	\|\| ch == ':';
451	}
452
453
454	/**
455	* Duplicate a spec string after unescaping it.
456	*
457	* This differs from RTStrDupN in that it uses RTMemTmpAlloc instead of
458	* RTMemAlloc.
459	*
460	* @returns String copy on success, NULL on failure.
461	* @param psz The string to duplicate.
462	* @param cch The number of bytes to duplicate.
463	* @param prc The status code variable to set on failure. (Leeps the
464	* code shorter. -lazy bird)
465	*/
466	DECLINLINE(char ) rtVfsChainSpecDupStrN(const char psz, size_t cch, int *prc)
467	{
468	char pszCopy = (char )RTMemTmpAlloc(cch + 1);
469	if (pszCopy)
470	{
471	if (!memchr(psz, '\\', cch))
472	{
473	/* Plain string, copy it raw. */
474	memcpy(pszCopy, psz, cch);
475	pszCopy[cch] = '\0';
476	}
477	else
478	{
479	/* Has escape sequences, must unescape it. */
480	char *pszDst = pszCopy;
481	while (cch-- > 0)
482	{
483	char ch = *psz++;
484	if (ch == '\\' && cch > 0)
485	{
486	char ch2 = *psz;
487	if (rtVfsChainSpecIsEscapableChar(ch2))
488	{
489	psz++;
490	cch--;
491	ch = ch2;
492	}
493	}
494	*pszDst++ = ch;
495	}
496	*pszDst = '\0';
497	}
498	}
499	else
500	*prc = VERR_NO_TMP_MEMORY;
501	return pszCopy;
502	}
503
504
505	/**
506	* Adds an empty element to the chain specification.
507	*
508	* The caller is responsible for filling it the element attributes.
509	*
510	* @returns Pointer to the new element on success, NULL on failure. The
511	* pointer is only valid till the next call to this function.
512	* @param pSpec The chain specification.
513	* @param prc The status code variable to set on failure. (Leeps the
514	* code shorter. -lazy bird)
515	*/
516	static PRTVFSCHAINELEMSPEC rtVfsChainSpecAddElement(PRTVFSCHAINSPEC pSpec, uint16_t offSpec, int *prc)
517	{
518	AssertPtr(pSpec);
519
520	/*
521	* Resize the element table if necessary.
522	*/
523	uint32_t const iElement = pSpec->cElements;
524	if ((iElement % 32) == 0)
525	{
526	PRTVFSCHAINELEMSPEC paNew = (PRTVFSCHAINELEMSPEC)RTMemTmpAlloc((iElement + 32) * sizeof(paNew[0]));
527	if (!paNew)
528	{
529	*prc = VERR_NO_TMP_MEMORY;
530	return NULL;
531	}
532
533	memcpy(paNew, pSpec->paElements, iElement * sizeof(paNew[0]));
534	RTMemTmpFree(pSpec->paElements);
535	pSpec->paElements = paNew;
536	}
537
538	/*
539	* Initialize and add the new element.
540	*/
541	PRTVFSCHAINELEMSPEC pElement = &pSpec->paElements[iElement];
542	pElement->pszProvider = NULL;
543	pElement->enmTypeIn = iElement ? pSpec->paElements[iElement - 1].enmType : RTVFSOBJTYPE_INVALID;
544	pElement->enmType = RTVFSOBJTYPE_INVALID;
545	pElement->offSpec = offSpec;
546	pElement->cchSpec = 0;
547	pElement->cArgs = 0;
548	pElement->paArgs = NULL;
549	pElement->pProvider = NULL;
550	pElement->hVfsObj = NIL_RTVFSOBJ;
551
552	pSpec->cElements = iElement + 1;
553	return pElement;
554	}
555
556
557	/**
558	* Adds an argument to the element spec.
559	*
560	* @returns IPRT status code.
561	* @param pElement The element.
562	* @param psz The start of the argument string.
563	* @param cch The length of the argument string, escape
564	* sequences counted twice.
565	*/
566	static int rtVfsChainSpecElementAddArg(PRTVFSCHAINELEMSPEC pElement, const char *psz, size_t cch, uint16_t offSpec)
567	{
568	uint32_t iArg = pElement->cArgs;
569	if ((iArg % 32) == 0)
570	{
571	PRTVFSCHAINELEMENTARG paNew = (PRTVFSCHAINELEMENTARG)RTMemTmpAlloc((iArg + 32) * sizeof(paNew[0]));
572	if (!paNew)
573	return VERR_NO_TMP_MEMORY;
574	memcpy(paNew, pElement->paArgs, iArg * sizeof(paNew[0]));
575	RTMemTmpFree(pElement->paArgs);
576	pElement->paArgs = paNew;
577	}
578
579	int rc = VINF_SUCCESS;
580	pElement->paArgs[iArg].psz = rtVfsChainSpecDupStrN(psz, cch, &rc);
581	pElement->paArgs[iArg].offSpec = offSpec;
582	pElement->cArgs = iArg + 1;
583	return rc;
584	}
585
586
587	RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec)
588	{
589	if (!pSpec)
590	return;
591
592	uint32_t i = pSpec->cElements;
593	while (i-- > 0)
594	{
595	uint32_t iArg = pSpec->paElements[i].cArgs;
596	while (iArg-- > 0)
597	RTMemTmpFree(pSpec->paElements[i].paArgs[iArg].psz);
598	RTMemTmpFree(pSpec->paElements[i].paArgs);
599	RTMemTmpFree(pSpec->paElements[i].pszProvider);
600	if (pSpec->paElements[i].hVfsObj != NIL_RTVFSOBJ)
601	{
602	RTVfsObjRelease(pSpec->paElements[i].hVfsObj);
603	pSpec->paElements[i].hVfsObj = NIL_RTVFSOBJ;
604	}
605	}
606
607	RTMemTmpFree(pSpec->paElements);
608	pSpec->paElements = NULL;
609	RTMemTmpFree(pSpec);
610	}
611
612
613	/**
614	* Checks if @a psz is pointing to the final element specification.
615	*
616	* @returns true / false.
617	* @param psz Start of an element or path.
618	* @param pcch Where to return the length.
619	*/
620	static bool rtVfsChainSpecIsFinalElement(const char psz, size_t pcch)
621	{
622	size_t off = 0;
623	char ch;
624	while ((ch = psz[off]) != '\0')
625	{
626	if (ch == '\|' \|\| ch == ':')
627	return false;
628	if ( ch == '\\'
629	&& rtVfsChainSpecIsEscapableChar(psz[off + 1]))
630	off++;
631	off++;
632	}
633	*pcch = off;
634	return off > 0;
635	}
636
637
638	/**
639	* Makes the final path element.
640	* @returns IPRT status code
641	* @param pElement The element.
642	* @param pszPath The path.
643	* @param cchPath The path length.
644	*/
645	static int rtVfsChainSpecMakeFinalPathElement(PRTVFSCHAINELEMSPEC pElement, const char *pszPath, size_t cchPath)
646	{
647	pElement->pszProvider = NULL;
648	pElement->enmType = RTVFSOBJTYPE_END;
649	pElement->cchSpec = (uint16_t)cchPath;
650	return rtVfsChainSpecElementAddArg(pElement, pszPath, cchPath, pElement->offSpec);
651	}
652
653
654	/**
655	* Finds the end of the argument string.
656	*
657	* @returns The offset of the end character relative to @a psz.
658	* @param psz The argument string.
659	* @param chCloseParen The closing parenthesis.
660	*/
661	static size_t rtVfsChainSpecFindArgEnd(const char *psz, char const chCloseParen)
662	{
663	size_t off = 0;
664	char ch;
665	while ( (ch = psz[off]) != '\0'
666	&& ch != ','
667	&& ch != chCloseParen)
668	{
669	if ( ch == '\\'
670	&& rtVfsChainSpecIsEscapableChar(psz[off+1]))
671	off++;
672	off++;
673	}
674	return off;
675	}
676
677
678	RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSOBJTYPE enmDesiredType,
679	PRTVFSCHAINSPEC ppSpec, uint32_t poffError)
680	{
681	if (poffError)
682	{
683	AssertPtrReturn(poffError, VERR_INVALID_POINTER);
684	*poffError = 0;
685	}
686	AssertPtrReturn(ppSpec, VERR_INVALID_POINTER);
687	*ppSpec = NULL;
688	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
689	AssertReturn(!(fFlags & ~RTVFSCHAIN_PF_VALID_MASK), VERR_INVALID_PARAMETER);
690	AssertReturn(enmDesiredType > RTVFSOBJTYPE_INVALID && enmDesiredType < RTVFSOBJTYPE_END, VERR_INVALID_PARAMETER);
691
692	/*
693	* Check the start of the specification and allocate an empty return spec.
694	*/
695	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1))
696	return VERR_VFS_CHAIN_NO_PREFIX;
697	const char *pszSrc = RTStrStripL(pszSpec + sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1);
698	if (!*pszSrc)
699	return VERR_VFS_CHAIN_EMPTY;
700
701	PRTVFSCHAINSPEC pSpec = rtVfsChainSpecAlloc();
702	if (!pSpec)
703	return VERR_NO_TMP_MEMORY;
704	pSpec->enmDesiredType = enmDesiredType;
705
706	/*
707	* Parse the spec one element at a time.
708	*/
709	int rc = VINF_SUCCESS;
710	while (*pszSrc && RT_SUCCESS(rc))
711	{
712	/*
713	* Digest element separator, except for the first element.
714	*/
715	if (pszSrc == '\|' \|\| pszSrc == ':')
716	{
717	if (pSpec->cElements != 0)
718	pszSrc = RTStrStripL(pszSrc + 1);
719	else
720	{
721	rc = VERR_VFS_CHAIN_LEADING_SEPARATOR;
722	break;
723	}
724	}
725	else if (pSpec->cElements != 0)
726	{
727	rc = VERR_VFS_CHAIN_EXPECTED_SEPARATOR;
728	break;
729	}
730
731	/*
732	* Ok, there should be an element here so add one to the return struct.
733	*/
734	PRTVFSCHAINELEMSPEC pElement = rtVfsChainSpecAddElement(pSpec, (uint16_t)(pszSrc - pszSpec), &rc);
735	if (!pElement)
736	break;
737
738	/*
739	* First up is the VFS object type followed by a parenthesis/curly, or
740	* this could be the trailing action. Alternatively, we could have a
741	* final path-only element here.
742	*/
743	size_t cch;
744	if (strncmp(pszSrc, "base", cch = 4) == 0)
745	pElement->enmType = RTVFSOBJTYPE_BASE;
746	else if (strncmp(pszSrc, "vfs", cch = 3) == 0)
747	pElement->enmType = RTVFSOBJTYPE_VFS;
748	else if (strncmp(pszSrc, "fss", cch = 3) == 0)
749	pElement->enmType = RTVFSOBJTYPE_FS_STREAM;
750	else if (strncmp(pszSrc, "ios", cch = 3) == 0)
751	pElement->enmType = RTVFSOBJTYPE_IO_STREAM;
752	else if (strncmp(pszSrc, "dir", cch = 3) == 0)
753	pElement->enmType = RTVFSOBJTYPE_DIR;
754	else if (strncmp(pszSrc, "file", cch = 4) == 0)
755	pElement->enmType = RTVFSOBJTYPE_FILE;
756	else if (strncmp(pszSrc, "sym", cch = 3) == 0)
757	pElement->enmType = RTVFSOBJTYPE_SYMLINK;
758	else
759	{
760	if (rtVfsChainSpecIsFinalElement(pszSrc, &cch))
761	rc = rtVfsChainSpecMakeFinalPathElement(pElement, pszSrc, cch);
762	else if (*pszSrc == '\0')
763	rc = VERR_VFS_CHAIN_TRAILING_SEPARATOR;
764	else
765	rc = VERR_VFS_CHAIN_UNKNOWN_TYPE;
766	break;
767	}
768
769	/* Check and skip past the parenthesis/curly. If not there, we might
770	have a final path element at our hands. */
771	char const chOpenParen = pszSrc[cch];
772	if (chOpenParen != '(' && chOpenParen != '{')
773	{
774	if (rtVfsChainSpecIsFinalElement(pszSrc, &cch))
775	rc = rtVfsChainSpecMakeFinalPathElement(pElement, pszSrc, cch);
776	else
777	rc = VERR_VFS_CHAIN_EXPECTED_LEFT_PARENTHESES;
778	break;
779	}
780	char const chCloseParen = (chOpenParen == '(' ? ')' : '}');
781	pszSrc = RTStrStripL(pszSrc + cch + 1);
782
783	/*
784	* The name of the element provider.
785	*/
786	cch = rtVfsChainSpecFindArgEnd(pszSrc, chCloseParen);
787	if (!cch)
788	{
789	rc = VERR_VFS_CHAIN_EXPECTED_PROVIDER_NAME;
790	break;
791	}
792	pElement->pszProvider = rtVfsChainSpecDupStrN(pszSrc, cch, &rc);
793	if (!pElement->pszProvider)
794	break;
795	pszSrc += cch;
796
797	/*
798	* The arguments.
799	*/
800	while (*pszSrc == ',')
801	{
802	pszSrc = RTStrStripL(pszSrc + 1);
803	cch = rtVfsChainSpecFindArgEnd(pszSrc, chCloseParen);
804	rc = rtVfsChainSpecElementAddArg(pElement, pszSrc, cch, (uint16_t)(pszSrc - pszSpec));
805	if (RT_FAILURE(rc))
806	break;
807	pszSrc += cch;
808	}
809	if (RT_FAILURE(rc))
810	break;
811
812	/* Must end with a right parentheses/curly. */
813	if (*pszSrc != chCloseParen)
814	{
815	rc = VERR_VFS_CHAIN_EXPECTED_RIGHT_PARENTHESES;
816	break;
817	}
818	pElement->cchSpec = (uint16_t)(pszSrc - pszSpec) - pElement->offSpec + 1;
819
820	pszSrc = RTStrStripL(pszSrc + 1);
821	}
822
823	#if 0
824	/*
825	* Dump the chain. Useful for debugging the above code.
826	*/
827	RTAssertMsg2("dbg: cElements=%d rc=%Rrc\n", pSpec->cElements, rc);
828	for (uint32_t i = 0; i < pSpec->cElements; i++)
829	{
830	uint32_t const cArgs = pSpec->paElements[i].cArgs;
831	RTAssertMsg2("dbg: #%u: enmTypeIn=%d enmType=%d cArgs=%d",
832	i, pSpec->paElements[i].enmTypeIn, pSpec->paElements[i].enmType, cArgs);
833	for (uint32_t j = 0; j < cArgs; j++)
834	RTAssertMsg2(j == 0 ? (cArgs > 1 ? " [%s" : " [%s]") : j + 1 < cArgs ? ", %s" : ", %s]",
835	pSpec->paElements[i].paArgs[j].psz);
836	RTAssertMsg2(" offSpec=%d cchSpec=%d", pSpec->paElements[i].offSpec, pSpec->paElements[i].cchSpec);
837	RTAssertMsg2(" spec: %.*s\n", pSpec->paElements[i].cchSpec, &pszSpec[pSpec->paElements[i].offSpec]);
838	}
839	#endif
840
841	/*
842	* Return the chain on success; Cleanup and set the error indicator on
843	* failure.
844	*/
845	if (RT_SUCCESS(rc))
846	*ppSpec = pSpec;
847	else
848	{
849	if (poffError)
850	*poffError = (uint32_t)(pszSrc - pszSpec);
851	RTVfsChainSpecFree(pSpec);
852	}
853	return rc;
854	}
855
856
857	/**
858	* Looks up @a pszProvider among the registered providers.
859	*
860	* @returns Pointer to registration record if found, NULL if not.
861	* @param pszProvider The provider.
862	*/
863	static PCRTVFSCHAINELEMENTREG rtVfsChainFindProviderLocked(const char *pszProvider)
864	{
865	PCRTVFSCHAINELEMENTREG pIterator;
866	RTListForEach(&g_rtVfsChainElementProviderList, pIterator, RTVFSCHAINELEMENTREG, ListEntry)
867	{
868	if (strcmp(pIterator->pszName, pszProvider) == 0)
869	return pIterator;
870	}
871	return NULL;
872	}
873
874
875	/**
876	* Does reusable object type matching.
877	*
878	* @returns true if the types matches, false if not.
879	* @param pElement The target element specification.
880	* @param pReuseElement The source element specification.
881	*/
882	static bool rtVfsChainMatchReusableType(PRTVFSCHAINELEMSPEC pElement, PRTVFSCHAINELEMSPEC pReuseElement)
883	{
884	if (pElement->enmType == pReuseElement->enmType)
885	return true;
886
887	/* File objects can always be cast to I/O streams. */
888	if ( pElement->enmType == RTVFSOBJTYPE_IO_STREAM
889	&& pReuseElement->enmType == RTVFSOBJTYPE_FILE)
890	return true;
891
892	/* I/O stream objects may be file objects. */
893	if ( pElement->enmType == RTVFSOBJTYPE_FILE
894	&& pReuseElement->enmType == RTVFSOBJTYPE_IO_STREAM)
895	{
896	RTVFSFILE hVfsFile = RTVfsObjToFile(pReuseElement->hVfsObj);
897	if (hVfsFile != NIL_RTVFSFILE)
898	{
899	RTVfsFileRelease(hVfsFile);
900	return true;
901	}
902	}
903	return false;
904	}
905
906
907	RTDECL(int) RTVfsChainSpecCheckAndSetup(PRTVFSCHAINSPEC pSpec, PCRTVFSCHAINSPEC pReuseSpec,
908	PRTVFSOBJ phVfsObj, const char *ppszFinalPath, uint32_t poffError, PRTERRINFO pErrInfo)
909	{
910	AssertPtrReturn(poffError, VERR_INVALID_POINTER);
911	*poffError = 0;
912	AssertPtrReturn(phVfsObj, VERR_INVALID_POINTER);
913	*phVfsObj = NIL_RTVFSOBJ;
914	AssertPtrReturn(ppszFinalPath, VERR_INVALID_POINTER);
915	*ppszFinalPath = NULL;
916	AssertPtrReturn(pSpec, VERR_INVALID_POINTER);
917	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
918
919	/*
920	* Check for final path-only component as we will not touch it yet.
921	*/
922	uint32_t cElements = pSpec->cElements;
923	if (cElements > 0)
924	{
925	if (pSpec->paElements[pSpec->cElements - 1].enmType == RTVFSOBJTYPE_END)
926	{
927	if (cElements > 1)
928	cElements--;
929	else
930	{
931	*ppszFinalPath = pSpec->paElements[0].paArgs[0].psz;
932	return VERR_VFS_CHAIN_PATH_ONLY;
933	}
934	}
935	}
936	else
937	return VERR_VFS_CHAIN_EMPTY;
938
939	/*
940	* Enter the critical section after making sure it has been initialized.
941	*/
942	int rc = RTOnce(&g_rtVfsChainElementInitOnce, rtVfsChainElementRegisterInit, NULL);
943	if (RT_SUCCESS(rc))
944	rc = RTCritSectRwEnterShared(&g_rtVfsChainElementCritSect);
945	if (RT_SUCCESS(rc))
946	{
947	/*
948	* Resolve and check each element first.
949	*/
950	for (uint32_t i = 0; i < cElements; i++)
951	{
952	PRTVFSCHAINELEMSPEC const pElement = &pSpec->paElements[i];
953	*poffError = pElement->offSpec;
954	pElement->pProvider = rtVfsChainFindProviderLocked(pElement->pszProvider);
955	if (pElement->pProvider)
956	{
957	rc = pElement->pProvider->pfnValidate(pElement->pProvider, pSpec, pElement, poffError, pErrInfo);
958	if (RT_SUCCESS(rc))
959	continue;
960	}
961	else
962	rc = VERR_VFS_CHAIN_PROVIDER_NOT_FOUND;
963	break;
964	}
965
966	/*
967	* Check that the desired type is compatible with the last element.
968	*/
969	if (RT_SUCCESS(rc))
970	{
971	PRTVFSCHAINELEMSPEC const pLast = &pSpec->paElements[cElements - 1];
972	if (cElements == pSpec->cElements)
973	{
974	if ( pLast->enmType == pSpec->enmDesiredType
975	\|\| pSpec->enmDesiredType == RTVFSOBJTYPE_BASE
976	\|\| ( pLast->enmType == RTVFSOBJTYPE_FILE
977	&& pSpec->enmDesiredType == RTVFSOBJTYPE_IO_STREAM) )
978	rc = VINF_SUCCESS;
979	else
980	{
981	*poffError = pLast->offSpec;
982	rc = VERR_VFS_CHAIN_FINAL_TYPE_MISMATCH;
983	}
984	}
985	/* Ends with a path-only element, so check the type of the element preceding it. */
986	else if ( pLast->enmType == RTVFSOBJTYPE_DIR
987	\|\| pLast->enmType == RTVFSOBJTYPE_VFS
988	\|\| pLast->enmType == RTVFSOBJTYPE_FS_STREAM)
989	rc = VINF_SUCCESS;
990	else
991	{
992	*poffError = pLast->offSpec;
993	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
994	}
995	}
996
997	if (RT_SUCCESS(rc))
998	{
999	/*
1000	* Try construct the chain.
1001	*/
1002	RTVFSOBJ hPrevVfsObj = NIL_RTVFSOBJ; /* No extra reference, kept in chain structure. */
1003	for (uint32_t i = 0; i < cElements; i++)
1004	{
1005	PRTVFSCHAINELEMSPEC const pElement = &pSpec->paElements[i];
1006	*poffError = pElement->offSpec;
1007
1008	/*
1009	* Try reuse the VFS objects at the start of the passed in reuse chain.
1010	*/
1011	if (!pReuseSpec)
1012	{ /* likely */ }
1013	else
1014	{
1015	if (i < pReuseSpec->cElements)
1016	{
1017	PRTVFSCHAINELEMSPEC const pReuseElement = &pReuseSpec->paElements[i];
1018	if (pReuseElement->hVfsObj != NIL_RTVFSOBJ)
1019	{
1020	if (strcmp(pElement->pszProvider, pReuseElement->pszProvider) == 0)
1021	{
1022	if (rtVfsChainMatchReusableType(pElement, pReuseElement))
1023	{
1024	if (pElement->pProvider->pfnCanReuseElement(pElement->pProvider, pSpec, pElement,
1025	pReuseSpec, pReuseElement))
1026	{
1027	uint32_t cRefs = RTVfsObjRetain(pReuseElement->hVfsObj);
1028	if (cRefs != UINT32_MAX)
1029	{
1030	pElement->hVfsObj = hPrevVfsObj = pReuseElement->hVfsObj;
1031	continue;
1032	}
1033	}
1034	}
1035	}
1036	}
1037	}
1038	pReuseSpec = NULL;
1039	}
1040
1041	/*
1042	* Instantiate a new VFS object.
1043	*/
1044	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1045	rc = pElement->pProvider->pfnInstantiate(pElement->pProvider, pSpec, pElement, hPrevVfsObj,
1046	&hVfsObj, poffError, pErrInfo);
1047	if (RT_FAILURE(rc))
1048	break;
1049	pElement->hVfsObj = hVfsObj;
1050	hPrevVfsObj = hVfsObj;
1051	}
1052
1053	/*
1054	* Add another reference to the final object and return.
1055	*/
1056	if (RT_SUCCESS(rc))
1057	{
1058	uint32_t cRefs = RTVfsObjRetain(hPrevVfsObj);
1059	AssertStmt(cRefs != UINT32_MAX, rc = VERR_VFS_CHAIN_IPE);
1060	*phVfsObj = hPrevVfsObj;
1061	*ppszFinalPath = cElements == pSpec->cElements ? NULL : pSpec->paElements[cElements].paArgs[0].psz;
1062	}
1063	}
1064
1065	int rc2 = RTCritSectRwLeaveShared(&g_rtVfsChainElementCritSect);
1066	if (RT_FAILURE(rc2) && RT_SUCCESS(rc))
1067	rc = rc2;
1068	}
1069	return rc;
1070	}
1071
1072
1073	RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor)
1074	{
1075	/*
1076	* Fend off wildlife.
1077	*/
1078	if (pRegRec == NULL)
1079	return VINF_SUCCESS;
1080	AssertPtrReturn(pRegRec, VERR_INVALID_POINTER);
1081	AssertMsgReturn(pRegRec->uVersion == RTVFSCHAINELEMENTREG_VERSION, ("%#x", pRegRec->uVersion), VERR_INVALID_POINTER);
1082	AssertMsgReturn(pRegRec->uEndMarker == RTVFSCHAINELEMENTREG_VERSION, ("%#zx", pRegRec->uEndMarker), VERR_INVALID_POINTER);
1083	AssertPtrReturn(pRegRec->pszName, VERR_INVALID_POINTER);
1084
1085	/*
1086	* Take the lock if that's safe.
1087	*/
1088	if (!fFromDtor)
1089	RTCritSectRwEnterExcl(&g_rtVfsChainElementCritSect);
1090	else if (!g_rtVfsChainElementProviderList.pNext)
1091	RTListInit(&g_rtVfsChainElementProviderList);
1092
1093	/*
1094	* Ok, remove it.
1095	*/
1096	int rc = VERR_NOT_FOUND;
1097	PRTVFSCHAINELEMENTREG pIterator, pIterNext;
1098	RTListForEachSafe(&g_rtVfsChainElementProviderList, pIterator, pIterNext, RTVFSCHAINELEMENTREG, ListEntry)
1099	{
1100	if (pIterator == pRegRec)
1101	{
1102	RTListNodeRemove(&pRegRec->ListEntry);
1103	rc = VINF_SUCCESS;
1104	break;
1105	}
1106	}
1107
1108	/*
1109	* Leave the lock and return.
1110	*/
1111	if (!fFromDtor)
1112	RTCritSectRwLeaveExcl(&g_rtVfsChainElementCritSect);
1113	return rc;
1114	}
1115
1116
1117	RTDECL(int) RTVfsChainOpenObj(const char *pszSpec, uint64_t fFileOpen, uint32_t fObjFlags,
1118	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo)
1119	{
1120	/*
1121	* Validate input.
1122	*/
1123	uint32_t offErrorIgn;
1124	if (!poffError)
1125	poffError = &offErrorIgn;
1126	*poffError = 0;
1127	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
1128	AssertReturn(*pszSpec != '\0', VERR_INVALID_PARAMETER);
1129	AssertPtrReturn(phVfsObj, VERR_INVALID_POINTER);
1130	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
1131
1132	int rc = rtFileRecalcAndValidateFlags(&fFileOpen);
1133	if (RT_FAILURE(rc))
1134	return rc;
1135	AssertMsgReturn( RTPATH_F_IS_VALID(fObjFlags, RTVFSOBJ_F_VALID_MASK)
1136	&& (fObjFlags & RTVFSOBJ_F_CREATE_MASK) <= RTVFSOBJ_F_CREATE_DIRECTORY,
1137	("fObjFlags=%#x\n", fObjFlags),
1138	VERR_INVALID_FLAGS);
1139
1140	/*
1141	* Try for a VFS chain first, falling back on regular file system stuff if it's just a path.
1142	*/
1143	PRTVFSCHAINSPEC pSpec = NULL;
1144	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) == 0)
1145	{
1146	rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_DIR, &pSpec, poffError);
1147	if (RT_FAILURE(rc))
1148	return rc;
1149
1150	Assert(pSpec->cElements > 0);
1151	if ( pSpec->cElements > 1
1152	\|\| pSpec->paElements[0].enmType != RTVFSOBJTYPE_END)
1153	{
1154	const char *pszFinal = NULL;
1155	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1156	pSpec->fOpenFile = fFileOpen;
1157	rc = RTVfsChainSpecCheckAndSetup(pSpec, NULL /pReuseSpec/, &hVfsObj, &pszFinal, poffError, pErrInfo);
1158	if (RT_SUCCESS(rc))
1159	{
1160	if (!pszFinal)
1161	{
1162	*phVfsObj = hVfsObj;
1163	rc = VINF_SUCCESS;
1164	}
1165	else
1166	{
1167	/*
1168	* Do a file open with the final path on the returned object.
1169	*/
1170	RTVFS hVfs = RTVfsObjToVfs(hVfsObj);
1171	RTVFSDIR hVfsDir = RTVfsObjToDir(hVfsObj);
1172	RTVFSFSSTREAM hVfsFss = RTVfsObjToFsStream(hVfsObj);
1173	if (hVfs != NIL_RTVFS)
1174	rc = RTVfsObjOpen(hVfs, pszFinal, fFileOpen, fObjFlags, phVfsObj);
1175	else if (hVfsDir != NIL_RTVFSDIR)
1176	rc = RTVfsDirOpenObj(hVfsDir, pszFinal, fFileOpen, fObjFlags, phVfsObj);
1177	else if (hVfsFss != NIL_RTVFSFSSTREAM)
1178	rc = VERR_NOT_IMPLEMENTED;
1179	else
1180	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
1181	RTVfsRelease(hVfs);
1182	RTVfsDirRelease(hVfsDir);
1183	RTVfsFsStrmRelease(hVfsFss);
1184	RTVfsObjRelease(hVfsObj);
1185	}
1186	}
1187
1188	RTVfsChainSpecFree(pSpec);
1189	return rc;
1190	}
1191
1192	/* Only a path element. */
1193	pszSpec = pSpec->paElements[0].paArgs[0].psz;
1194	}
1195
1196	/*
1197	* Path to regular file system.
1198	* Go via the directory VFS wrapper to avoid duplicating code.
1199	*/
1200	RTVFSDIR hVfsParentDir = NIL_RTVFSDIR;
1201	const char *pszFilename;
1202	if (RTPathHasPath(pszSpec))
1203	{
1204	char *pszCopy = RTStrDup(pszSpec);
1205	if (pszCopy)
1206	{
1207	RTPathStripFilename(pszCopy);
1208	rc = RTVfsDirOpenNormal(pszCopy, 0 /fOpen/, &hVfsParentDir);
1209	RTStrFree(pszCopy);
1210	}
1211	else
1212	rc = VERR_NO_STR_MEMORY;
1213	pszFilename = RTPathFilename(pszSpec);
1214	}
1215	else
1216	{
1217	pszFilename = pszSpec;
1218	rc = RTVfsDirOpenNormal(".", 0 /fOpen/, &hVfsParentDir);
1219	}
1220	if (RT_SUCCESS(rc))
1221	{
1222	rc = RTVfsDirOpenObj(hVfsParentDir, pszFilename, fFileOpen, fObjFlags, phVfsObj);
1223	RTVfsDirRelease(hVfsParentDir);
1224	}
1225
1226	RTVfsChainSpecFree(pSpec);
1227	return rc;
1228	}
1229
1230
1231	RTDECL(int) RTVfsChainOpenDir(const char *pszSpec, uint32_t fOpen,
1232	PRTVFSDIR phVfsDir, uint32_t *poffError, PRTERRINFO pErrInfo)
1233	{
1234	uint32_t offErrorIgn;
1235	if (!poffError)
1236	poffError = &offErrorIgn;
1237	*poffError = 0;
1238	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
1239	AssertReturn(*pszSpec != '\0', VERR_INVALID_PARAMETER);
1240	AssertPtrReturn(phVfsDir, VERR_INVALID_POINTER);
1241	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
1242
1243	/*
1244	* Try for a VFS chain first, falling back on regular file system stuff if it's just a path.
1245	*/
1246	int rc;
1247	PRTVFSCHAINSPEC pSpec = NULL;
1248	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) == 0)
1249	{
1250	rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_DIR, &pSpec, poffError);
1251	if (RT_FAILURE(rc))
1252	return rc;
1253
1254	Assert(pSpec->cElements > 0);
1255	if ( pSpec->cElements > 1
1256	\|\| pSpec->paElements[0].enmType != RTVFSOBJTYPE_END)
1257	{
1258	const char *pszFinal = NULL;
1259	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1260	pSpec->fOpenFile = RTFILE_O_READ;
1261	rc = RTVfsChainSpecCheckAndSetup(pSpec, NULL /pReuseSpec/, &hVfsObj, &pszFinal, poffError, pErrInfo);
1262	if (RT_SUCCESS(rc))
1263	{
1264	if (!pszFinal)
1265	{
1266	/* Try convert it to a directory object and we're done. */
1267	*phVfsDir = RTVfsObjToDir(hVfsObj);
1268	if (*phVfsDir)
1269	rc = VINF_SUCCESS;
1270	else
1271	rc = VERR_VFS_CHAIN_CAST_FAILED;
1272	}
1273	else
1274	{
1275	/*
1276	* Do a file open with the final path on the returned object.
1277	*/
1278	RTVFS hVfs = RTVfsObjToVfs(hVfsObj);
1279	RTVFSDIR hVfsDir = RTVfsObjToDir(hVfsObj);
1280	RTVFSFSSTREAM hVfsFss = RTVfsObjToFsStream(hVfsObj);
1281	if (hVfs != NIL_RTVFS)
1282	rc = RTVfsDirOpen(hVfs, pszFinal, fOpen, phVfsDir);
1283	else if (hVfsDir != NIL_RTVFSDIR)
1284	rc = RTVfsDirOpenDir(hVfsDir, pszFinal, fOpen, phVfsDir);
1285	else if (hVfsFss != NIL_RTVFSFSSTREAM)
1286	rc = VERR_NOT_IMPLEMENTED;
1287	else
1288	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
1289	RTVfsRelease(hVfs);
1290	RTVfsDirRelease(hVfsDir);
1291	RTVfsFsStrmRelease(hVfsFss);
1292	}
1293	RTVfsObjRelease(hVfsObj);
1294	}
1295
1296	RTVfsChainSpecFree(pSpec);
1297	return rc;
1298	}
1299
1300	/* Only a path element. */
1301	pszSpec = pSpec->paElements[0].paArgs[0].psz;
1302	}
1303
1304	/*
1305	* Path to regular file system.
1306	*/
1307	rc = RTVfsDirOpenNormal(pszSpec, fOpen, phVfsDir);
1308
1309	RTVfsChainSpecFree(pSpec);
1310	return rc;
1311	}
1312
1313
1314	RTDECL(int) RTVfsChainOpenParentDir(const char pszSpec, uint32_t fOpen, PRTVFSDIR phVfsDir, const char *ppszChild,
1315	uint32_t *poffError, PRTERRINFO pErrInfo)
1316	{
1317	uint32_t offErrorIgn;
1318	if (!poffError)
1319	poffError = &offErrorIgn;
1320	*poffError = 0;
1321	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
1322	AssertReturn(*pszSpec != '\0', VERR_INVALID_PARAMETER);
1323	AssertPtrReturn(phVfsDir, VERR_INVALID_POINTER);
1324	AssertPtrReturn(ppszChild, VERR_INVALID_POINTER);
1325	*ppszChild = NULL;
1326	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
1327
1328	/*
1329	* Process the spec from the end, trying to find the child part of it.
1330	* We cannot use RTPathFilename here because we must ignore trailing slashes.
1331	*/
1332	const char * const pszEnd = RTStrEnd(pszSpec, RTSTR_MAX);
1333	const char *pszChild = pszEnd;
1334	while ( pszChild != pszSpec
1335	&& RTPATH_IS_SLASH(pszChild[-1]))
1336	pszChild--;
1337	while ( pszChild != pszSpec
1338	&& !RTPATH_IS_SLASH(pszChild[-1])
1339	&& !RTPATH_IS_VOLSEP(pszChild[-1]))
1340	pszChild--;
1341	size_t const cchChild = pszEnd - pszChild;
1342	*ppszChild = pszChild;
1343
1344	/*
1345	* Try for a VFS chain first, falling back on regular file system stuff if it's just a path.
1346	*/
1347	int rc;
1348	PRTVFSCHAINSPEC pSpec = NULL;
1349	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) == 0)
1350	{
1351	rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_DIR, &pSpec, poffError);
1352	if (RT_FAILURE(rc))
1353	return rc;
1354
1355	Assert(pSpec->cElements > 0);
1356	if ( pSpec->cElements > 1
1357	\|\| pSpec->paElements[0].enmType != RTVFSOBJTYPE_END)
1358	{
1359	/*
1360	* Check that it ends with a path-only element and that this in turn ends with
1361	* what pszChild points to. (We cannot easiy figure out the parent part of
1362	* an element that isn't path-only, so we don't bother trying try.)
1363	*/
1364	PRTVFSCHAINELEMSPEC pLast = &pSpec->paElements[pSpec->cElements - 1];
1365	if (pLast->pszProvider == NULL)
1366	{
1367	size_t cchFinal = strlen(pLast->paArgs[0].psz);
1368	if ( cchFinal >= cchChild
1369	&& memcmp(&pLast->paArgs[0].psz[cchFinal - cchChild], pszChild, cchChild + 1) == 0)
1370	{
1371	/*
1372	* Drop the child part so we have a path to the parent, then setup the chain.
1373	*/
1374	if (cchFinal > cchChild)
1375	pLast->paArgs[0].psz[cchFinal - cchChild] = '\0';
1376	else
1377	pSpec->cElements--;
1378
1379	const char *pszFinal = NULL;
1380	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1381	pSpec->fOpenFile = fOpen;
1382	rc = RTVfsChainSpecCheckAndSetup(pSpec, NULL /pReuseSpec/, &hVfsObj, &pszFinal, poffError, pErrInfo);
1383	if (RT_SUCCESS(rc))
1384	{
1385	if (!pszFinal)
1386	{
1387	Assert(cchFinal == cchChild);
1388
1389	/* Try convert it to a file object and we're done. */
1390	*phVfsDir = RTVfsObjToDir(hVfsObj);
1391	if (*phVfsDir)
1392	rc = VINF_SUCCESS;
1393	else
1394	rc = VERR_VFS_CHAIN_CAST_FAILED;
1395	}
1396	else
1397	{
1398	/*
1399	* Do a file open with the final path on the returned object.
1400	*/
1401	RTVFS hVfs = RTVfsObjToVfs(hVfsObj);
1402	RTVFSDIR hVfsDir = RTVfsObjToDir(hVfsObj);
1403	RTVFSFSSTREAM hVfsFss = RTVfsObjToFsStream(hVfsObj);
1404	if (hVfs != NIL_RTVFS)
1405	rc = RTVfsDirOpen(hVfs, pszFinal, fOpen, phVfsDir);
1406	else if (hVfsDir != NIL_RTVFSDIR)
1407	rc = RTVfsDirOpenDir(hVfsDir, pszFinal, fOpen, phVfsDir);
1408	else if (hVfsFss != NIL_RTVFSFSSTREAM)
1409	rc = VERR_NOT_IMPLEMENTED;
1410	else
1411	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
1412	RTVfsRelease(hVfs);
1413	RTVfsDirRelease(hVfsDir);
1414	RTVfsFsStrmRelease(hVfsFss);
1415	}
1416	RTVfsObjRelease(hVfsObj);
1417	}
1418	}
1419	else
1420	rc = VERR_VFS_CHAIN_TOO_SHORT_FOR_PARENT;
1421	}
1422	else
1423	rc = VERR_VFS_CHAIN_NOT_PATH_ONLY;
1424
1425	RTVfsChainSpecFree(pSpec);
1426	return rc;
1427	}
1428
1429	/* Only a path element. */
1430	pszSpec = pSpec->paElements[0].paArgs[0].psz;
1431	}
1432
1433	/*
1434	* Path to regular file system.
1435	*/
1436	if (RTPathHasPath(pszSpec))
1437	{
1438	char *pszCopy = RTStrDup(pszSpec);
1439	if (pszCopy)
1440	{
1441	RTPathStripFilename(pszCopy);
1442	rc = RTVfsDirOpenNormal(pszCopy, fOpen, phVfsDir);
1443	RTStrFree(pszCopy);
1444	}
1445	else
1446	rc = VERR_NO_STR_MEMORY;
1447	}
1448	else
1449	rc = RTVfsDirOpenNormal(".", fOpen, phVfsDir);
1450
1451	RTVfsChainSpecFree(pSpec);
1452	return rc;
1453
1454	}
1455
1456
1457	RTDECL(int) RTVfsChainOpenFile(const char *pszSpec, uint64_t fOpen,
1458	PRTVFSFILE phVfsFile, uint32_t *poffError, PRTERRINFO pErrInfo)
1459	{
1460	uint32_t offErrorIgn;
1461	if (!poffError)
1462	poffError = &offErrorIgn;
1463	*poffError = 0;
1464	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
1465	AssertReturn(*pszSpec != '\0', VERR_INVALID_PARAMETER);
1466	AssertPtrReturn(phVfsFile, VERR_INVALID_POINTER);
1467	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
1468
1469	/*
1470	* Try for a VFS chain first, falling back on regular file system stuff if it's just a path.
1471	*/
1472	int rc;
1473	PRTVFSCHAINSPEC pSpec = NULL;
1474	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) == 0)
1475	{
1476	rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_FILE, &pSpec, poffError);
1477	if (RT_FAILURE(rc))
1478	return rc;
1479
1480	Assert(pSpec->cElements > 0);
1481	if ( pSpec->cElements > 1
1482	\|\| pSpec->paElements[0].enmType != RTVFSOBJTYPE_END)
1483	{
1484	const char *pszFinal = NULL;
1485	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1486	pSpec->fOpenFile = fOpen;
1487	rc = RTVfsChainSpecCheckAndSetup(pSpec, NULL /pReuseSpec/, &hVfsObj, &pszFinal, poffError, pErrInfo);
1488	if (RT_SUCCESS(rc))
1489	{
1490	if (!pszFinal)
1491	{
1492	/* Try convert it to a file object and we're done. */
1493	*phVfsFile = RTVfsObjToFile(hVfsObj);
1494	if (*phVfsFile)
1495	rc = VINF_SUCCESS;
1496	else
1497	rc = VERR_VFS_CHAIN_CAST_FAILED;
1498	}
1499	else
1500	{
1501	/*
1502	* Do a file open with the final path on the returned object.
1503	*/
1504	RTVFS hVfs = RTVfsObjToVfs(hVfsObj);
1505	RTVFSDIR hVfsDir = RTVfsObjToDir(hVfsObj);
1506	RTVFSFSSTREAM hVfsFss = RTVfsObjToFsStream(hVfsObj);
1507	if (hVfs != NIL_RTVFS)
1508	rc = RTVfsFileOpen(hVfs, pszFinal, fOpen, phVfsFile);
1509	else if (hVfsDir != NIL_RTVFSDIR)
1510	rc = RTVfsDirOpenFile(hVfsDir, pszFinal, fOpen, phVfsFile);
1511	else if (hVfsFss != NIL_RTVFSFSSTREAM)
1512	rc = VERR_NOT_IMPLEMENTED;
1513	else
1514	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
1515	RTVfsRelease(hVfs);
1516	RTVfsDirRelease(hVfsDir);
1517	RTVfsFsStrmRelease(hVfsFss);
1518	}
1519	RTVfsObjRelease(hVfsObj);
1520	}
1521
1522	RTVfsChainSpecFree(pSpec);
1523	return rc;
1524	}
1525
1526	/* Only a path element. */
1527	pszSpec = pSpec->paElements[0].paArgs[0].psz;
1528	}
1529
1530	/*
1531	* Path to regular file system.
1532	*/
1533	RTFILE hFile;
1534	rc = RTFileOpen(&hFile, pszSpec, fOpen);
1535	if (RT_SUCCESS(rc))
1536	{
1537	RTVFSFILE hVfsFile;
1538	rc = RTVfsFileFromRTFile(hFile, fOpen, false /fLeaveOpen/, &hVfsFile);
1539	if (RT_SUCCESS(rc))
1540	*phVfsFile = hVfsFile;
1541	else
1542	RTFileClose(hFile);
1543	}
1544
1545	RTVfsChainSpecFree(pSpec);
1546	return rc;
1547	}
1548
1549
1550	RTDECL(int) RTVfsChainOpenIoStream(const char *pszSpec, uint64_t fOpen,
1551	PRTVFSIOSTREAM phVfsIos, uint32_t *poffError, PRTERRINFO pErrInfo)
1552	{
1553	uint32_t offErrorIgn;
1554	if (!poffError)
1555	poffError = &offErrorIgn;
1556	*poffError = 0;
1557	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
1558	AssertReturn(*pszSpec != '\0', VERR_INVALID_PARAMETER);
1559	AssertPtrReturn(phVfsIos, VERR_INVALID_POINTER);
1560	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
1561
1562	/*
1563	* Try for a VFS chain first, falling back on regular file system stuff if it's just a path.
1564	*/
1565	int rc;
1566	PRTVFSCHAINSPEC pSpec = NULL;
1567	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) == 0)
1568	{
1569	rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_IO_STREAM, &pSpec, poffError);
1570	if (RT_FAILURE(rc))
1571	return rc;
1572
1573	Assert(pSpec->cElements > 0);
1574	if ( pSpec->cElements > 1
1575	\|\| pSpec->paElements[0].enmType != RTVFSOBJTYPE_END)
1576	{
1577	const char *pszFinal = NULL;
1578	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1579	pSpec->fOpenFile = fOpen;
1580	rc = RTVfsChainSpecCheckAndSetup(pSpec, NULL /pReuseSpec/, &hVfsObj, &pszFinal, poffError, pErrInfo);
1581	if (RT_SUCCESS(rc))
1582	{
1583	if (!pszFinal)
1584	{
1585	/* Try convert it to an I/O object and we're done. */
1586	*phVfsIos = RTVfsObjToIoStream(hVfsObj);
1587	if (*phVfsIos)
1588	rc = VINF_SUCCESS;
1589	else
1590	rc = VERR_VFS_CHAIN_CAST_FAILED;
1591	}
1592	else
1593	{
1594	/*
1595	* Do a file open with the final path on the returned object.
1596	*/
1597	RTVFS hVfs = RTVfsObjToVfs(hVfsObj);
1598	RTVFSDIR hVfsDir = RTVfsObjToDir(hVfsObj);
1599	RTVFSFSSTREAM hVfsFss = RTVfsObjToFsStream(hVfsObj);
1600	RTVFSFILE hVfsFile = NIL_RTVFSFILE;
1601	if (hVfs != NIL_RTVFS)
1602	rc = RTVfsFileOpen(hVfs, pszFinal, fOpen, &hVfsFile);
1603	else if (hVfsDir != NIL_RTVFSDIR)
1604	rc = RTVfsDirOpenFile(hVfsDir, pszFinal, fOpen, &hVfsFile);
1605	else if (hVfsFss != NIL_RTVFSFSSTREAM)
1606	rc = VERR_NOT_IMPLEMENTED;
1607	else
1608	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
1609	if (RT_SUCCESS(rc))
1610	{
1611	*phVfsIos = RTVfsFileToIoStream(hVfsFile);
1612	if (*phVfsIos)
1613	rc = VINF_SUCCESS;
1614	else
1615	rc = VERR_VFS_CHAIN_CAST_FAILED;
1616	RTVfsFileRelease(hVfsFile);
1617	}
1618	RTVfsRelease(hVfs);
1619	RTVfsDirRelease(hVfsDir);
1620	RTVfsFsStrmRelease(hVfsFss);
1621	}
1622	RTVfsObjRelease(hVfsObj);
1623	}
1624
1625	RTVfsChainSpecFree(pSpec);
1626	return rc;
1627	}
1628
1629	/* Only a path element. */
1630	pszSpec = pSpec->paElements[0].paArgs[0].psz;
1631	}
1632
1633	/*
1634	* Path to regular file system.
1635	*/
1636	RTFILE hFile;
1637	rc = RTFileOpen(&hFile, pszSpec, fOpen);
1638	if (RT_SUCCESS(rc))
1639	{
1640	RTVFSFILE hVfsFile;
1641	rc = RTVfsFileFromRTFile(hFile, fOpen, false /fLeaveOpen/, &hVfsFile);
1642	if (RT_SUCCESS(rc))
1643	{
1644	*phVfsIos = RTVfsFileToIoStream(hVfsFile);
1645	RTVfsFileRelease(hVfsFile);
1646	}
1647	else
1648	RTFileClose(hFile);
1649	}
1650
1651	RTVfsChainSpecFree(pSpec);
1652	return rc;
1653	}
1654
1655
1656	/**
1657	* The equivalent of RTPathQueryInfoEx
1658	*/
1659	RTDECL(int) RTVfsChainQueryInfo(const char *pszSpec, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAdditionalAttribs,
1660	uint32_t fFlags, uint32_t *poffError, PRTERRINFO pErrInfo)
1661	{
1662	uint32_t offErrorIgn;
1663	if (!poffError)
1664	poffError = &offErrorIgn;
1665	*poffError = 0;
1666	AssertPtrReturn(pszSpec, VERR_INVALID_POINTER);
1667	AssertReturn(*pszSpec != '\0', VERR_INVALID_PARAMETER);
1668	AssertPtrReturn(pObjInfo, VERR_INVALID_POINTER);
1669	AssertReturn(enmAdditionalAttribs >= RTFSOBJATTRADD_NOTHING && enmAdditionalAttribs <= RTFSOBJATTRADD_LAST,
1670	VERR_INVALID_PARAMETER);
1671	AssertPtrNullReturn(pErrInfo, VERR_INVALID_POINTER);
1672
1673	/*
1674	* Try for a VFS chain first, falling back on regular file system stuff if it's just a path.
1675	*/
1676	int rc;
1677	PRTVFSCHAINSPEC pSpec = NULL;
1678	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) == 0)
1679	{
1680	rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_BASE, &pSpec, poffError);
1681	if (RT_FAILURE(rc))
1682	return rc;
1683
1684	Assert(pSpec->cElements > 0);
1685	if ( pSpec->cElements > 1
1686	\|\| pSpec->paElements[0].enmType != RTVFSOBJTYPE_END)
1687	{
1688	const char *pszFinal = NULL;
1689	RTVFSOBJ hVfsObj = NIL_RTVFSOBJ;
1690	pSpec->fOpenFile = RTFILE_O_READ \| RTFILE_O_OPEN;
1691	rc = RTVfsChainSpecCheckAndSetup(pSpec, NULL /pReuseSpec/, &hVfsObj, &pszFinal, poffError, pErrInfo);
1692	if (RT_SUCCESS(rc))
1693	{
1694	if (!pszFinal)
1695	{
1696	/*
1697	* Do the job on the final object.
1698	*/
1699	rc = RTVfsObjQueryInfo(hVfsObj, pObjInfo, enmAdditionalAttribs);
1700	}
1701	else
1702	{
1703	/*
1704	* Do a path query operation on the penultimate object.
1705	*/
1706	RTVFS hVfs = RTVfsObjToVfs(hVfsObj);
1707	RTVFSDIR hVfsDir = RTVfsObjToDir(hVfsObj);
1708	RTVFSFSSTREAM hVfsFss = RTVfsObjToFsStream(hVfsObj);
1709	if (hVfs != NIL_RTVFS)
1710	rc = RTVfsQueryPathInfo(hVfs, pszFinal, pObjInfo, enmAdditionalAttribs, fFlags);
1711	else if (hVfsDir != NIL_RTVFSDIR)
1712	rc = RTVfsDirQueryPathInfo(hVfsDir, pszFinal, pObjInfo, enmAdditionalAttribs, fFlags);
1713	else if (hVfsFss != NIL_RTVFSFSSTREAM)
1714	rc = VERR_NOT_SUPPORTED;
1715	else
1716	rc = VERR_VFS_CHAIN_TYPE_MISMATCH_PATH_ONLY;
1717	RTVfsRelease(hVfs);
1718	RTVfsDirRelease(hVfsDir);
1719	RTVfsFsStrmRelease(hVfsFss);
1720	}
1721	RTVfsObjRelease(hVfsObj);
1722	}
1723
1724	RTVfsChainSpecFree(pSpec);
1725	return rc;
1726	}
1727
1728	/* Only a path element. */
1729	pszSpec = pSpec->paElements[0].paArgs[0].psz;
1730	}
1731
1732	/*
1733	* Path to regular file system.
1734	*/
1735	rc = RTPathQueryInfoEx(pszSpec, pObjInfo, enmAdditionalAttribs, fFlags);
1736
1737	RTVfsChainSpecFree(pSpec);
1738	return rc;
1739	}
1740
1741
1742	RTDECL(bool) RTVfsChainIsSpec(const char *pszSpec)
1743	{
1744	return pszSpec
1745	&& strncmp(pszSpec, RT_STR_TUPLE(RTVFSCHAIN_SPEC_PREFIX)) == 0;
1746	}
1747
1748
1749	RTDECL(int) RTVfsChainQueryFinalPath(const char pszSpec, char ppszFinalPath, uint32_t poffError)
1750	{
1751	/* Make sure we've got an error info variable. */
1752	uint32_t offErrorIgn;
1753	if (!poffError)
1754	poffError = &offErrorIgn;
1755	*poffError = 0;
1756
1757	/*
1758	* If not chain specifier, just duplicate the input and return.
1759	*/
1760	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) != 0)
1761	return RTStrDupEx(ppszFinalPath, pszSpec);
1762
1763	/*
1764	* Parse it and check out the last element.
1765	*/
1766	PRTVFSCHAINSPEC pSpec = NULL;
1767	int rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_BASE, &pSpec, poffError);
1768	if (RT_SUCCESS(rc))
1769	{
1770	PCRTVFSCHAINELEMSPEC pLast = &pSpec->paElements[pSpec->cElements - 1];
1771	if (pLast->pszProvider == NULL)
1772	rc = RTStrDupEx(ppszFinalPath, pLast->paArgs[0].psz);
1773	else
1774	{
1775	rc = VERR_VFS_CHAIN_NOT_PATH_ONLY;
1776	*poffError = pLast->offSpec;
1777	}
1778	RTVfsChainSpecFree(pSpec);
1779	}
1780	return rc;
1781	}
1782
1783
1784	RTDECL(int) RTVfsChainSplitOffFinalPath(char pszSpec, char ppszSpec, char ppszFinalPath, uint32_t poffError)
1785	{
1786	/* Make sure we've got an error info variable. */
1787	uint32_t offErrorIgn;
1788	if (!poffError)
1789	poffError = &offErrorIgn;
1790	*poffError = 0;
1791
1792	/*
1793	* If not chain specifier, just duplicate the input and return.
1794	*/
1795	if (strncmp(pszSpec, RTVFSCHAIN_SPEC_PREFIX, sizeof(RTVFSCHAIN_SPEC_PREFIX) - 1) != 0)
1796	{
1797	*ppszSpec = NULL;
1798	*ppszFinalPath = pszSpec;
1799	return VINF_SUCCESS;
1800	}
1801
1802	/*
1803	* Parse it and check out the last element.
1804	*/
1805	PRTVFSCHAINSPEC pSpec = NULL;
1806	int rc = RTVfsChainSpecParse(pszSpec, 0 /fFlags/, RTVFSOBJTYPE_BASE, &pSpec, poffError);
1807	if (RT_SUCCESS(rc))
1808	{
1809	Assert(pSpec->cElements > 0);
1810	PCRTVFSCHAINELEMSPEC pLast = &pSpec->paElements[pSpec->cElements - 1];
1811	if (pLast->pszProvider == NULL)
1812	{
1813	char *psz = &pszSpec[pLast->offSpec];
1814	*ppszFinalPath = psz;
1815	if (pSpec->cElements > 1)
1816	{
1817	*ppszSpec = pszSpec;
1818
1819	/* Remove the separator and any whitespace around it. */
1820	while ( psz != pszSpec
1821	&& RT_C_IS_SPACE(psz[-1]))
1822	psz--;
1823	if ( psz != pszSpec
1824	&& ( psz[-1] == ':'
1825	\|\| psz[-1] == '\|'))
1826	psz--;
1827	while ( psz != pszSpec
1828	&& RT_C_IS_SPACE(psz[-1]))
1829	psz--;
1830	*psz = '\0';
1831	}
1832	else
1833	*ppszSpec = NULL;
1834	}
1835	else
1836	{
1837	*ppszFinalPath = NULL;
1838	*ppszSpec = pszSpec;
1839	}
1840	RTVfsChainSpecFree(pSpec);
1841	}
1842	else
1843	{
1844	*ppszSpec = NULL;
1845	*ppszFinalPath = NULL;
1846	}
1847	return rc;
1848	}
1849

Note: See TracBrowser for help on using the repository browser.

source: vbox/trunk/src/VBox/Runtime/common/vfs/vfschain.cpp@ 74525

Download in other formats: