reactos/ntoskrnl/ob/object.c

   1 /* $Id: object.c,v 1.52 2002/07/17 21:04:56 dwelch Exp $
   2  *
   3  * COPYRIGHT:     See COPYING in the top level directory
   4  * PROJECT:       ReactOS kernel
   5  * FILE:          ntoskrnl/ob/object.c
   6  * PURPOSE:       Implements generic object managment functions
   7  * PROGRAMMER:    David Welch (welch@cwcom.net)
   8  * UPDATE HISTORY:
   9  *               10/06/98: Created
  10  */
  11
  12 /* INCLUDES *****************************************************************/
  13
  14 #include <ddk/ntddk.h>
  15 #include <roscfg.h>
  16 #include <internal/ob.h>
  17 #include <internal/ps.h>
  18 #include <internal/id.h>
  19 #include <internal/ke.h>
  20
  21 #define NDEBUG
  22 #include <internal/debug.h>
  23
  24 /* FUNCTIONS ************************************************************/
  25
  26 PVOID HEADER_TO_BODY(POBJECT_HEADER obj)
  27 {
  28    return(((void *)obj)+sizeof(OBJECT_HEADER)-sizeof(COMMON_BODY_HEADER));
  29 }
  30
  31 POBJECT_HEADER BODY_TO_HEADER(PVOID body)
  32 {
  33    PCOMMON_BODY_HEADER chdr = (PCOMMON_BODY_HEADER)body;
  34    return(CONTAINING_RECORD((&(chdr->Type)),OBJECT_HEADER,Type));
  35 }
  36
  37
  38 /**********************************************************************
  39  * NAME                                                 PRIVATE
  40  *      ObInitializeObject
  41  *
  42  * DESCRIPTION
  43  *
  44  * ARGUMENTS
  45  *
  46  * RETURN VALUE
  47  */
  48 VOID ObInitializeObject(POBJECT_HEADER ObjectHeader,
  49                         PHANDLE Handle,
  50                         ACCESS_MASK DesiredAccess,
  51                         POBJECT_TYPE Type,
  52                         POBJECT_ATTRIBUTES ObjectAttributes)
  53 {
  54    ObjectHeader->HandleCount = 0;
  55    ObjectHeader->RefCount = 1;
  56    ObjectHeader->ObjectType = Type;
  57    if (ObjectAttributes != NULL &&
  58        ObjectAttributes->Attributes & OBJ_PERMANENT)
  59      {
  60         ObjectHeader->Permanent = TRUE;
  61      }
  62    else
  63      {
  64         ObjectHeader->Permanent = FALSE;
  65      }
  66    RtlInitUnicodeString(&(ObjectHeader->Name),NULL);
  67    if (Handle != NULL)
  68      {
  69         ObCreateHandle(PsGetCurrentProcess(),
  70                        HEADER_TO_BODY(ObjectHeader),
  71                        DesiredAccess,
  72                        ObjectAttributes && (ObjectAttributes->Attributes & OBJ_INHERIT) ? TRUE : FALSE,
  73                        Handle);
  74      }
  75 }
  76
  77
  78 /**********************************************************************
  79  * NAME                                                 PRIVATE
  80  *      ObFindObject@16
  81  *
  82  * DESCRIPTION
  83  *
  84  * ARGUMENTS
  85  *      ObjectAttributes
  86  *
  87  *      ReturnedObject
  88  *
  89  *      RemainigPath
  90  *              Pointer to a unicode string that will contain the
  91  *              remaining path if the function returns successfully.
  92  *              The caller must free the buffer after use by calling
  93  *              RtlFreeUnicodeString ().
  94  *
  95  *      ObjectType
  96  *              Optional pointer to an object type. This is used to
  97  *              descide if a symbolic link object will be parsed or not.
  98  *
  99  * RETURN VALUE
 100  */
 101 NTSTATUS ObFindObject(POBJECT_ATTRIBUTES ObjectAttributes,
 102                       PVOID* ReturnedObject,
 103                       PUNICODE_STRING RemainingPath,
 104                       POBJECT_TYPE ObjectType)
 105 {
 106    PVOID NextObject;
 107    PVOID CurrentObject;
 108    PVOID RootObject;
 109    POBJECT_HEADER CurrentHeader;
 110    NTSTATUS Status;
 111    PWSTR Path;
 112    PWSTR current;
 113    UNICODE_STRING PathString;
 114
 115    DPRINT("ObFindObject(ObjectAttributes %x, ReturnedObject %x, "
 116           "RemainingPath %x)\n",ObjectAttributes,ReturnedObject,RemainingPath);
 117    DPRINT("ObjectAttributes->ObjectName %wZ\n",
 118           ObjectAttributes->ObjectName);
 119
 120    RtlInitUnicodeString (RemainingPath, NULL);
 121
 122    if (ObjectAttributes->RootDirectory == NULL)
 123      {
 124         ObReferenceObjectByPointer(NameSpaceRoot,
 125                                    DIRECTORY_TRAVERSE,
 126                                    NULL,
 127                                    UserMode);
 128         CurrentObject = NameSpaceRoot;
 129      }
 130    else
 131      {
 132         Status = ObReferenceObjectByHandle(ObjectAttributes->RootDirectory,
 133                                            DIRECTORY_TRAVERSE,
 134                                            NULL,
 135                                            UserMode,
 136                                            &CurrentObject,
 137                                            NULL);
 138         if (!NT_SUCCESS(Status))
 139           {
 140              return(Status);
 141           }
 142      }
 143
 144    Path = ObjectAttributes->ObjectName->Buffer;
 145
 146    if (Path[0] == 0)
 147      {
 148         *ReturnedObject = CurrentObject;
 149         return(STATUS_SUCCESS);
 150      }
 151
 152    if ((ObjectAttributes->RootDirectory == NULL) && (Path[0] != '\\'))
 153      {
 154         ObDereferenceObject(CurrentObject);
 155         return(STATUS_UNSUCCESSFUL);
 156      }
 157
 158    if (Path)
 159      {
 160         RtlCreateUnicodeString (&PathString, Path);
 161         current = PathString.Buffer;
 162      }
 163    else
 164      {
 165         RtlInitUnicodeString (&PathString, NULL);
 166         current = NULL;
 167      }
 168
 169    RootObject = CurrentObject;
 170
 171    while (TRUE)
 172      {
 173         DPRINT("current %S\n",current);
 174         CurrentHeader = BODY_TO_HEADER(CurrentObject);
 175
 176         DPRINT("Current ObjectType %wZ\n",
 177                &CurrentHeader->ObjectType->TypeName);
 178
 179         if (CurrentHeader->ObjectType->Parse == NULL)
 180           {
 181              DPRINT("Current object can't parse\n");
 182              break;
 183           }
 184         Status = CurrentHeader->ObjectType->Parse(CurrentObject,
 185                                                   &NextObject,
 186                                                   &PathString,
 187                                                   &current,
 188                                                   ObjectAttributes->Attributes);
 189         if (Status == STATUS_REPARSE)
 190           {
 191              /* reparse the object path */
 192              NextObject = RootObject;
 193              current = PathString.Buffer;
 194
 195              ObReferenceObjectByPointer(NextObject,
 196                                         DIRECTORY_TRAVERSE,
 197                                         NULL,
 198                                         UserMode);
 199           }
 200
 201         if (NextObject == NULL)
 202           {
 203              break;
 204           }
 205         ObDereferenceObject(CurrentObject);
 206         CurrentObject = NextObject;
 207      }
 208
 209    if (current)
 210       RtlCreateUnicodeString (RemainingPath, current);
 211    RtlFreeUnicodeString (&PathString);
 212    *ReturnedObject = CurrentObject;
 213
 214    return(STATUS_SUCCESS);
 215 }
 216
 217
 218 /**********************************************************************
 219  * NAME                                                 EXPORTED
 220  *      ObCreateObject@36
 221  *
 222  * DESCRIPTION
 223  *
 224  * ARGUMENTS
 225  *
 226  * RETURN VALUE
 227  */
 228 NTSTATUS STDCALL
 229 ObCreateObject(OUT PHANDLE Handle,
 230                IN ACCESS_MASK DesiredAccess,
 231                IN POBJECT_ATTRIBUTES ObjectAttributes,
 232                IN POBJECT_TYPE Type,
 233                OUT PVOID *Object)
 234 {
 235   PVOID Parent = NULL;
 236   UNICODE_STRING RemainingPath;
 237   POBJECT_HEADER Header;
 238   POBJECT_HEADER ParentHeader = NULL;
 239   NTSTATUS Status;
 240   BOOLEAN ObjectAttached = FALSE;
 241
 242   assert_irql(APC_LEVEL);
 243
 244   DPRINT("ObCreateObject(Handle %x, ObjectAttributes %x, Type %x)\n",
 245          Handle, ObjectAttributes, Type);
 246   if (ObjectAttributes != NULL &&
 247       ObjectAttributes->ObjectName != NULL)
 248     {
 249       DPRINT("ObjectAttributes->ObjectName->Buffer %S\n",
 250              ObjectAttributes->ObjectName->Buffer);
 251     }
 252
 253   if (ObjectAttributes != NULL &&
 254       ObjectAttributes->ObjectName != NULL)
 255     {
 256       Status = ObFindObject(ObjectAttributes,
 257                             &Parent,
 258                             &RemainingPath,
 259                             NULL);
 260       if (!NT_SUCCESS(Status))
 261         {
 262           DPRINT("ObFindObject() failed! (Status 0x%x)\n", Status);
 263           return(Status);
 264         }
 265     }
 266   else
 267     {
 268       RtlInitUnicodeString(&RemainingPath, NULL);
 269     }
 270
 271   RtlMapGenericMask(&DesiredAccess,
 272                     Type->Mapping);
 273
 274   Header = (POBJECT_HEADER)ExAllocatePoolWithTag(NonPagedPool,
 275                                                  OBJECT_ALLOC_SIZE(Type),
 276                                                  Type->Tag);
 277   ObInitializeObject(Header,
 278                      NULL,
 279                      DesiredAccess,
 280                      Type,
 281                      ObjectAttributes);
 282
 283   if (Parent != NULL)
 284     {
 285       ParentHeader = BODY_TO_HEADER(Parent);
 286     }
 287
 288   if (ParentHeader != NULL &&
 289       ParentHeader->ObjectType == ObDirectoryType &&
 290       RemainingPath.Buffer != NULL)
 291     {
 292       ObpAddEntryDirectory(Parent,
 293                            Header,
 294                            RemainingPath.Buffer+1);
 295       ObjectAttached = TRUE;
 296     }
 297
 298   if ((Header->ObjectType != NULL) &&
 299       (Header->ObjectType->Create != NULL))
 300     {
 301       DPRINT("Calling %x\n", Header->ObjectType->Create);
 302       Status = Header->ObjectType->Create(HEADER_TO_BODY(Header),
 303                                           Parent,
 304                                           RemainingPath.Buffer,
 305                                           ObjectAttributes);
 306       if (!NT_SUCCESS(Status))
 307         {
 308           if (ObjectAttached == TRUE)
 309             {
 310               ObpRemoveEntryDirectory(Header);
 311             }
 312           if (Parent)
 313             {
 314               ObDereferenceObject(Parent);
 315             }
 316           RtlFreeUnicodeString(&Header->Name);
 317           RtlFreeUnicodeString(&RemainingPath);
 318           ExFreePool(Header);
 319           return(Status);
 320         }
 321     }
 322   RtlFreeUnicodeString( &RemainingPath );
 323
 324   if (Object != NULL)
 325     {
 326       *Object = HEADER_TO_BODY(Header);
 327     }
 328
 329   if (Handle != NULL)
 330   {
 331      ObCreateHandle(PsGetCurrentProcess(),
 332                     *Object,
 333                     DesiredAccess,
 334                     ObjectAttributes && (ObjectAttributes->Attributes & OBJ_INHERIT) ? TRUE : FALSE,
 335                     Handle);
 336   }
 337
 338   return(STATUS_SUCCESS);
 339 }
 340
 341
 342 NTSTATUS STDCALL
 343 ObReferenceObjectByPointer(IN PVOID Object,
 344                            IN ACCESS_MASK DesiredAccess,
 345                            IN POBJECT_TYPE ObjectType,
 346                            IN KPROCESSOR_MODE AccessMode)
 347 /*
 348  * FUNCTION: Increments the pointer reference count for a given object
 349  * ARGUMENTS:
 350  *         ObjectBody = Object's body
 351  *         DesiredAccess = Desired access to the object
 352  *         ObjectType = Points to the object type structure
 353  *         AccessMode = Type of access check to perform
 354  * RETURNS: Status
 355  */
 356 {
 357    POBJECT_HEADER Header;
 358
 359 //   DPRINT("ObReferenceObjectByPointer(Object %x, ObjectType %x)\n",
 360 //        Object,ObjectType);
 361
 362    Header = BODY_TO_HEADER(Object);
 363
 364    if (ObjectType != NULL && Header->ObjectType != ObjectType)
 365      {
 366         DPRINT("Failed %x (type was %x %S) should be %x %S\n",
 367                 Header,
 368                 Header->ObjectType,
 369                 Header->ObjectType->TypeName.Buffer,
 370                 ObjectType,
 371     ObjectType->TypeName.Buffer);
 372         return(STATUS_UNSUCCESSFUL);
 373      }
 374    if (Header->ObjectType == PsProcessType)
 375      {
 376         DPRINT("Ref p 0x%x refcount %d type %x ",
 377                 Object, Header->RefCount, PsProcessType);
 378         DPRINT("eip %x\n", ((PULONG)&Object)[-1]);
 379      }
 380    if (Header->ObjectType == PsThreadType)
 381      {
 382         DPRINT("Deref t 0x%x with refcount %d type %x ",
 383                 Object, Header->RefCount, PsThreadType);
 384         DPRINT("eip %x\n", ((PULONG)&Object)[-1]);
 385      }
 386
 387    InterlockedIncrement(&Header->RefCount);
 388
 389    return(STATUS_SUCCESS);
 390 }
 391
 392
 393 NTSTATUS STDCALL
 394 ObOpenObjectByPointer(IN POBJECT Object,
 395                       IN ULONG HandleAttributes,
 396                       IN PACCESS_STATE PassedAccessState,
 397                       IN ACCESS_MASK DesiredAccess,
 398                       IN POBJECT_TYPE ObjectType,
 399                       IN KPROCESSOR_MODE AccessMode,
 400                       OUT PHANDLE Handle)
 401 {
 402    NTSTATUS Status;
 403
 404    DPRINT("ObOpenObjectByPointer()\n");
 405
 406    Status = ObReferenceObjectByPointer(Object,
 407                                        0,
 408                                        ObjectType,
 409                                        AccessMode);
 410    if (!NT_SUCCESS(Status))
 411      {
 412         return Status;
 413      }
 414
 415    Status = ObCreateHandle(PsGetCurrentProcess(),
 416                            Object,
 417                            DesiredAccess,
 418                            HandleAttributes & OBJ_INHERIT,
 419                            Handle);
 420
 421    ObDereferenceObject(Object);
 422
 423    return STATUS_SUCCESS;
 424 }
 425
 426
 427 static NTSTATUS
 428 ObpPerformRetentionChecks(POBJECT_HEADER Header)
 429 {
 430 //  DPRINT("ObPerformRetentionChecks(Header %x), RefCount %d, HandleCount %d\n",
 431 //        Header,Header->RefCount,Header->HandleCount);
 432
 433   if (Header->RefCount < 0)
 434     {
 435       CPRINT("Object %x/%x has invalid reference count (%d)\n",
 436              Header, HEADER_TO_BODY(Header), Header->RefCount);
 437       KeBugCheck(0);
 438     }
 439   if (Header->HandleCount < 0)
 440     {
 441       CPRINT("Object %x/%x has invalid handle count (%d)\n",
 442              Header, HEADER_TO_BODY(Header), Header->HandleCount);
 443       KeBugCheck(0);
 444     }
 445
 446   if (Header->RefCount == 0 &&
 447       Header->HandleCount == 0 &&
 448       Header->Permanent == FALSE)
 449     {
 450       if (Header->ObjectType != NULL &&
 451           Header->ObjectType->Delete != NULL)
 452         {
 453           Header->ObjectType->Delete(HEADER_TO_BODY(Header));
 454         }
 455       if (Header->Name.Buffer != NULL)
 456         {
 457           ObpRemoveEntryDirectory(Header);
 458           RtlFreeUnicodeString(&Header->Name);
 459         }
 460       DPRINT("ObPerformRetentionChecks() = Freeing object\n");
 461       ExFreePool(Header);
 462     }
 463   return(STATUS_SUCCESS);
 464 }
 465
 466
 467 /**********************************************************************
 468  * NAME                                                 EXPORTED
 469  *      ObfReferenceObject@4
 470  *
 471  * DESCRIPTION
 472  *      Increments a given object's reference count and performs
 473  *      retention checks.
 474  *
 475  * ARGUMENTS
 476  *  ObjectBody = Body of the object.
 477  *
 478  * RETURN VALUE
 479  *      None.
 480  */
 481 VOID FASTCALL
 482 ObfReferenceObject(IN PVOID Object)
 483 {
 484   POBJECT_HEADER Header;
 485
 486   assert(Object);
 487
 488   Header = BODY_TO_HEADER(Object);
 489
 490   InterlockedIncrement(&Header->RefCount);
 491
 492   ObpPerformRetentionChecks(Header);
 493 }
 494
 495
 496 /**********************************************************************
 497  * NAME                                                 EXPORTED
 498  *      ObfDereferenceObject@4
 499  *
 500  * DESCRIPTION
 501  *      Decrements a given object's reference count and performs
 502  *      retention checks.
 503  *
 504  * ARGUMENTS
 505  *      ObjectBody = Body of the object.
 506  *
 507  * RETURN VALUE
 508  *      None.
 509  */
 510 VOID FASTCALL
 511 ObfDereferenceObject(IN PVOID Object)
 512 {
 513   POBJECT_HEADER Header;
 514   extern POBJECT_TYPE PsProcessType;
 515
 516   assert(Object);
 517
 518   Header = BODY_TO_HEADER(Object);
 519
 520   if (Header->ObjectType == PsProcessType)
 521     {
 522       DPRINT("Deref p 0x%x with refcount %d type %x ",
 523              Object, Header->RefCount, PsProcessType);
 524       DPRINT("eip %x\n", ((PULONG)&Object)[-1]);
 525     }
 526   if (Header->ObjectType == PsThreadType)
 527     {
 528       DPRINT("Deref t 0x%x with refcount %d type %x ",
 529              Object, Header->RefCount, PsThreadType);
 530       DPRINT("eip %x\n", ((PULONG)&Object)[-1]);
 531     }
 532
 533   InterlockedDecrement(&Header->RefCount);
 534
 535   ObpPerformRetentionChecks(Header);
 536 }
 537
 538
 539 /**********************************************************************
 540  * NAME                                                 EXPORTED
 541  *      ObGetObjectPointerCount@4
 542  *
 543  * DESCRIPTION
 544  *      Retrieves the pointer(reference) count of the given object.
 545  *
 546  * ARGUMENTS
 547  *      ObjectBody = Body of the object.
 548  *
 549  * RETURN VALUE
 550  *      Reference count.
 551  */
 552 ULONG STDCALL
 553 ObGetObjectPointerCount(PVOID Object)
 554 {
 555   POBJECT_HEADER Header;
 556
 557   assert(Object);
 558   Header = BODY_TO_HEADER(Object);
 559
 560   return(Header->RefCount);
 561 }
 562
 563
 564 /**********************************************************************
 565  * NAME                                                 INTERNAL
 566  *      ObGetObjectHandleCount@4
 567  *
 568  * DESCRIPTION
 569  *      Retrieves the handle count of the given object.
 570  *
 571  * ARGUMENTS
 572  *      ObjectBody = Body of the object.
 573  *
 574  * RETURN VALUE
 575  *      Reference count.
 576  */
 577 ULONG
 578 ObGetObjectHandleCount(PVOID Object)
 579 {
 580   POBJECT_HEADER Header;
 581
 582   assert(Object);
 583   Header = BODY_TO_HEADER(Object);
 584
 585   return(Header->HandleCount);
 586 }
 587
 588 /* EOF */