1 /*
2 * PROJECT: ReactOS Kernel
3 * LICENSE: GPL - See COPYING in the top level directory
4 * FILE: ntoskrnl/fsrtl/filtrctx.c
5 * PURPOSE: File Stream Filter Context support for File System Drivers
6 * PROGRAMMERS: Pierre Schweitzer (pierre.schweitzer@reactos.org)
7 */
8
9 /* INCLUDES ******************************************************************/
10
11 #include <ntoskrnl.h>
12 #define NDEBUG
13 #include <debug.h>
14
15 /* PRIVATE FUNCTIONS *********************************************************/
16
17 typedef struct _FILE_OBJECT_FILTER_CONTEXTS
18 {
19 FAST_MUTEX FilterContextsMutex;
20 LIST_ENTRY FilterContexts;
21 } FILE_OBJECT_FILTER_CONTEXTS, *PFILE_OBJECT_FILTER_CONTEXTS;
22
23 /*
24 * @implemented
25 */
26 VOID
27 NTAPI
FsRtlPTeardownPerFileObjectContexts(IN PFILE_OBJECT FileObject)28 FsRtlPTeardownPerFileObjectContexts(IN PFILE_OBJECT FileObject)
29 {
30 PFILE_OBJECT_FILTER_CONTEXTS FOContext = NULL;
31
32 ASSERT(FileObject);
33
34 if (!(FOContext = IoGetFileObjectFilterContext(FileObject)))
35 {
36 return;
37 }
38
39 ASSERT(IoChangeFileObjectFilterContext(FileObject, FOContext, FALSE) == STATUS_SUCCESS);
40 ASSERT(IsListEmpty(&(FOContext->FilterContexts)));
41
42 ExFreePoolWithTag(FOContext, 'FOCX');
43 }
44
45
46 /* PUBLIC FUNCTIONS **********************************************************/
47
48 /*++
49 * @name FsRtlIsPagingFile
50 * @implemented NT 5.2
51 *
52 * The FsRtlIsPagingFile routine checks if the FileObject is a Paging File.
53 *
54 * @param FileObject
55 * A pointer to the File Object to be tested.
56 *
57 * @return TRUE if the File is a Paging File, FALSE otherwise.
58 *
59 * @remarks None.
60 *
61 *--*/
62 LOGICAL
63 NTAPI
FsRtlIsPagingFile(IN PFILE_OBJECT FileObject)64 FsRtlIsPagingFile(IN PFILE_OBJECT FileObject)
65 {
66 return MmIsFileObjectAPagingFile(FileObject);
67 }
68
69 /*
70 * @implemented
71 */
72 PFSRTL_PER_FILEOBJECT_CONTEXT
73 NTAPI
FsRtlLookupPerFileObjectContext(IN PFILE_OBJECT FileObject,IN PVOID OwnerId OPTIONAL,IN PVOID InstanceId OPTIONAL)74 FsRtlLookupPerFileObjectContext(IN PFILE_OBJECT FileObject,
75 IN PVOID OwnerId OPTIONAL,
76 IN PVOID InstanceId OPTIONAL)
77 {
78 PLIST_ENTRY NextEntry;
79 PFILE_OBJECT_FILTER_CONTEXTS FOContext = NULL;
80 PFSRTL_PER_FILEOBJECT_CONTEXT TmpPerFOContext, PerFOContext = NULL;
81
82 if (!FileObject || !(FOContext = IoGetFileObjectFilterContext(FileObject)))
83 {
84 return NULL;
85 }
86
87 ExAcquireFastMutex(&(FOContext->FilterContextsMutex));
88
89 /* If list is empty, no need to browse it */
90 if (!IsListEmpty(&(FOContext->FilterContexts)))
91 {
92 for (NextEntry = FOContext->FilterContexts.Flink;
93 NextEntry != &(FOContext->FilterContexts);
94 NextEntry = NextEntry->Flink)
95 {
96 /* If we don't have any criteria for search, first entry will be enough */
97 if (!OwnerId && !InstanceId)
98 {
99 PerFOContext = (PFSRTL_PER_FILEOBJECT_CONTEXT)NextEntry;
100 break;
101 }
102 /* Else, we've to find something that matches with the parameters. */
103 else
104 {
105 TmpPerFOContext = CONTAINING_RECORD(NextEntry, FSRTL_PER_FILEOBJECT_CONTEXT, Links);
106 if ((InstanceId && TmpPerFOContext->InstanceId == InstanceId && TmpPerFOContext->OwnerId == OwnerId) ||
107 (OwnerId && TmpPerFOContext->OwnerId == OwnerId))
108 {
109 PerFOContext = TmpPerFOContext;
110 break;
111 }
112 }
113 }
114 }
115
116 ExReleaseFastMutex(&(FOContext->FilterContextsMutex));
117
118 return PerFOContext;
119 }
120
121 /*
122 * @implemented
123 */
124 PFSRTL_PER_STREAM_CONTEXT
125 NTAPI
FsRtlLookupPerStreamContextInternal(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader,IN PVOID OwnerId OPTIONAL,IN PVOID InstanceId OPTIONAL)126 FsRtlLookupPerStreamContextInternal(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader,
127 IN PVOID OwnerId OPTIONAL,
128 IN PVOID InstanceId OPTIONAL)
129 {
130 PLIST_ENTRY NextEntry;
131 PFSRTL_PER_STREAM_CONTEXT TmpPerStreamContext, PerStreamContext = NULL;
132
133 ASSERT(AdvFcbHeader);
134 ASSERT(FlagOn(AdvFcbHeader->Flags2, FSRTL_FLAG2_SUPPORTS_FILTER_CONTEXTS));
135
136 ExAcquireFastMutex(AdvFcbHeader->FastMutex);
137
138 /* If list is empty, no need to browse it */
139 if (!IsListEmpty(&(AdvFcbHeader->FilterContexts)))
140 {
141 for (NextEntry = AdvFcbHeader->FilterContexts.Flink;
142 NextEntry != &(AdvFcbHeader->FilterContexts);
143 NextEntry = NextEntry->Flink)
144 {
145 /* If we don't have any criteria for search, first entry will be enough */
146 if (!OwnerId && !InstanceId)
147 {
148 PerStreamContext = (PFSRTL_PER_STREAM_CONTEXT)NextEntry;
149 break;
150 }
151 /* Else, we've to find something that matches with the parameters. */
152 else
153 {
154 TmpPerStreamContext = CONTAINING_RECORD(NextEntry, FSRTL_PER_STREAM_CONTEXT, Links);
155 if ((InstanceId && TmpPerStreamContext->InstanceId == InstanceId && TmpPerStreamContext->OwnerId == OwnerId) ||
156 (OwnerId && TmpPerStreamContext->OwnerId == OwnerId))
157 {
158 PerStreamContext = TmpPerStreamContext;
159 break;
160 }
161 }
162 }
163 }
164
165 ExReleaseFastMutex(AdvFcbHeader->FastMutex);
166
167 return PerStreamContext;
168 }
169
170 /*
171 * @implemented
172 */
173 NTSTATUS
174 NTAPI
FsRtlInsertPerFileObjectContext(IN PFILE_OBJECT FileObject,IN PFSRTL_PER_FILEOBJECT_CONTEXT Ptr)175 FsRtlInsertPerFileObjectContext(IN PFILE_OBJECT FileObject,
176 IN PFSRTL_PER_FILEOBJECT_CONTEXT Ptr)
177 {
178 PFILE_OBJECT_FILTER_CONTEXTS FOContext = NULL;
179 NTSTATUS Status;
180
181 if (!FileObject)
182 {
183 return STATUS_INVALID_PARAMETER;
184 }
185
186 if (!(FileObject->Flags & FO_FILE_OBJECT_HAS_EXTENSION))
187 {
188 return STATUS_INVALID_DEVICE_REQUEST;
189 }
190
191 /* Get filter contexts */
192 FOContext = IoGetFileObjectFilterContext(FileObject);
193 if (!FOContext)
194 {
195 /* If there's none, allocate new structure */
196 FOContext = ExAllocatePoolWithTag(NonPagedPool, sizeof(FILE_OBJECT_FILTER_CONTEXTS), 'FOCX');
197 if (!FOContext)
198 {
199 return STATUS_INSUFFICIENT_RESOURCES;
200 }
201
202 /* Initialize it */
203 ExInitializeFastMutex(&(FOContext->FilterContextsMutex));
204 InitializeListHead(&(FOContext->FilterContexts));
205
206 /* Set it */
207 Status = IoChangeFileObjectFilterContext(FileObject, FOContext, TRUE);
208 if (!NT_SUCCESS(Status))
209 {
210 /* If it fails, it means that someone else has set it in the meanwhile */
211 ExFreePoolWithTag(FOContext, 'FOCX');
212
213 /* So, we can get it */
214 FOContext = IoGetFileObjectFilterContext(FileObject);
215 if (!FOContext)
216 {
217 /* If we fall down here, something went very bad. This shouldn't happen */
218 ASSERT(FALSE);
219 return STATUS_UNSUCCESSFUL;
220 }
221 }
222 }
223
224 /* Finally, insert */
225 ExAcquireFastMutex(&(FOContext->FilterContextsMutex));
226 InsertHeadList(&(FOContext->FilterContexts), &(Ptr->Links));
227 ExReleaseFastMutex(&(FOContext->FilterContextsMutex));
228
229 return STATUS_SUCCESS;
230 }
231
232 /*
233 * @implemented
234 */
235 NTSTATUS
236 NTAPI
FsRtlInsertPerStreamContext(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader,IN PFSRTL_PER_STREAM_CONTEXT PerStreamContext)237 FsRtlInsertPerStreamContext(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader,
238 IN PFSRTL_PER_STREAM_CONTEXT PerStreamContext)
239 {
240 if (!(AdvFcbHeader) || !(AdvFcbHeader->Flags2 & FSRTL_FLAG2_SUPPORTS_FILTER_CONTEXTS))
241 {
242 return STATUS_INVALID_DEVICE_REQUEST;
243 }
244
245 ExAcquireFastMutex(AdvFcbHeader->FastMutex);
246 InsertHeadList(&(AdvFcbHeader->FilterContexts), &(PerStreamContext->Links));
247 ExReleaseFastMutex(AdvFcbHeader->FastMutex);
248 return STATUS_SUCCESS;
249 }
250
251 /*
252 * @implemented
253 */
254 PFSRTL_PER_FILEOBJECT_CONTEXT
255 NTAPI
FsRtlRemovePerFileObjectContext(IN PFILE_OBJECT FileObject,IN PVOID OwnerId OPTIONAL,IN PVOID InstanceId OPTIONAL)256 FsRtlRemovePerFileObjectContext(IN PFILE_OBJECT FileObject,
257 IN PVOID OwnerId OPTIONAL,
258 IN PVOID InstanceId OPTIONAL)
259 {
260 PLIST_ENTRY NextEntry;
261 PFILE_OBJECT_FILTER_CONTEXTS FOContext = NULL;
262 PFSRTL_PER_FILEOBJECT_CONTEXT TmpPerFOContext, PerFOContext = NULL;
263
264 if (!FileObject || !(FOContext = IoGetFileObjectFilterContext(FileObject)))
265 {
266 return NULL;
267 }
268
269 ExAcquireFastMutex(&(FOContext->FilterContextsMutex));
270
271 /* If list is empty, no need to browse it */
272 if (!IsListEmpty(&(FOContext->FilterContexts)))
273 {
274 for (NextEntry = FOContext->FilterContexts.Flink;
275 NextEntry != &(FOContext->FilterContexts);
276 NextEntry = NextEntry->Flink)
277 {
278 /* If we don't have any criteria for search, first entry will be enough */
279 if (!OwnerId && !InstanceId)
280 {
281 PerFOContext = (PFSRTL_PER_FILEOBJECT_CONTEXT)NextEntry;
282 break;
283 }
284 /* Else, we've to find something that matches with the parameters. */
285 else
286 {
287 TmpPerFOContext = CONTAINING_RECORD(NextEntry, FSRTL_PER_FILEOBJECT_CONTEXT, Links);
288 if ((InstanceId && TmpPerFOContext->InstanceId == InstanceId && TmpPerFOContext->OwnerId == OwnerId) ||
289 (OwnerId && TmpPerFOContext->OwnerId == OwnerId))
290 {
291 PerFOContext = TmpPerFOContext;
292 break;
293 }
294 }
295 }
296
297 /* Finally remove entry from list */
298 if (PerFOContext)
299 {
300 RemoveEntryList(&(PerFOContext->Links));
301 }
302 }
303
304 ExReleaseFastMutex(&(FOContext->FilterContextsMutex));
305
306 return PerFOContext;
307 }
308
309 /*
310 * @implemented
311 */
312 PFSRTL_PER_STREAM_CONTEXT
313 NTAPI
FsRtlRemovePerStreamContext(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader,IN PVOID OwnerId OPTIONAL,IN PVOID InstanceId OPTIONAL)314 FsRtlRemovePerStreamContext(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader,
315 IN PVOID OwnerId OPTIONAL,
316 IN PVOID InstanceId OPTIONAL)
317 {
318 PLIST_ENTRY NextEntry;
319 PFSRTL_PER_STREAM_CONTEXT TmpPerStreamContext, PerStreamContext = NULL;
320
321 if (!(AdvFcbHeader) || !(AdvFcbHeader->Flags2 & FSRTL_FLAG2_SUPPORTS_FILTER_CONTEXTS))
322 {
323 return NULL;
324 }
325
326 ExAcquireFastMutex(AdvFcbHeader->FastMutex);
327 /* If list is empty, no need to browse it */
328 if (!IsListEmpty(&(AdvFcbHeader->FilterContexts)))
329 {
330 for (NextEntry = AdvFcbHeader->FilterContexts.Flink;
331 NextEntry != &(AdvFcbHeader->FilterContexts);
332 NextEntry = NextEntry->Flink)
333 {
334 /* If we don't have any criteria for search, first entry will be enough */
335 if (!OwnerId && !InstanceId)
336 {
337 PerStreamContext = (PFSRTL_PER_STREAM_CONTEXT)NextEntry;
338 break;
339 }
340 /* Else, we've to find something that matches with the parameters. */
341 else
342 {
343 TmpPerStreamContext = CONTAINING_RECORD(NextEntry, FSRTL_PER_STREAM_CONTEXT, Links);
344 if ((InstanceId && TmpPerStreamContext->InstanceId == InstanceId && TmpPerStreamContext->OwnerId == OwnerId) ||
345 (OwnerId && TmpPerStreamContext->OwnerId == OwnerId))
346 {
347 PerStreamContext = TmpPerStreamContext;
348 break;
349 }
350 }
351 }
352
353 /* Finally remove entry from list */
354 if (PerStreamContext)
355 {
356 RemoveEntryList(&(PerStreamContext->Links));
357 }
358 }
359 ExReleaseFastMutex(AdvFcbHeader->FastMutex);
360
361 return PerStreamContext;
362
363 }
364
365 /*
366 * @implemented
367 */
368 VOID
369 NTAPI
FsRtlTeardownPerStreamContexts(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader)370 FsRtlTeardownPerStreamContexts(IN PFSRTL_ADVANCED_FCB_HEADER AdvFcbHeader)
371 {
372 PLIST_ENTRY NextEntry;
373 volatile BOOLEAN IsMutexLocked = FALSE;
374 PFSRTL_PER_STREAM_CONTEXT PerStreamContext;
375
376 _SEH2_TRY
377 {
378 /* Acquire mutex to deal with the list */
379 ExAcquireFastMutex(AdvFcbHeader->FastMutex);
380 IsMutexLocked = TRUE;
381
382 /* While there are items... */
383 while (!IsListEmpty(&(AdvFcbHeader->FilterContexts)))
384 {
385 /* ...remove one */
386 NextEntry = RemoveHeadList(&(AdvFcbHeader->FilterContexts));
387 PerStreamContext = CONTAINING_RECORD(NextEntry, FSRTL_PER_STREAM_CONTEXT, Links);
388
389 /* Release mutex before calling callback */
390 ExReleaseFastMutex(AdvFcbHeader->FastMutex);
391 IsMutexLocked = FALSE;
392
393 /* Call the callback */
394 ASSERT(PerStreamContext->FreeCallback);
395 (*PerStreamContext->FreeCallback)(PerStreamContext);
396
397 /* Relock the list to continue */
398 ExAcquireFastMutex(AdvFcbHeader->FastMutex);
399 IsMutexLocked = TRUE;
400 }
401 }
402 _SEH2_FINALLY
403 {
404 /* If mutex was locked, release */
405 if (IsMutexLocked)
406 {
407 ExReleaseFastMutex(AdvFcbHeader->FastMutex);
408 }
409 }
410 _SEH2_END;
411 }
412