reactos/ntoskrnl/io/symlink.c

   1 /* $Id: symlink.c,v 1.25 2002/02/19 14:06:36 ekohl Exp $
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/io/symlink.c
   6  * PURPOSE:         Implements symbolic links
   7  * PROGRAMMER:      David Welch (welch@mcmail.com)
   8  * UPDATE HISTORY:
   9  *                  Created 22/05/98
  10  */
  11
  12 /* INCLUDES *****************************************************************/
  13
  14 #include <limits.h>
  15 #include <ddk/ntddk.h>
  16 #include <internal/pool.h>
  17
  18 #define NDEBUG
  19 #include <internal/debug.h>
  20
  21 /* GLOBALS ******************************************************************/
  22
  23 typedef struct
  24 {
  25         CSHORT                  Type;
  26         CSHORT                  Size;
  27         UNICODE_STRING          TargetName;
  28         OBJECT_ATTRIBUTES       Target;
  29 } SYMLNK_OBJECT, *PSYMLNK_OBJECT;
  30
  31 POBJECT_TYPE IoSymbolicLinkType = NULL;
  32
  33 static GENERIC_MAPPING IopSymbolicLinkMapping = {
  34         STANDARD_RIGHTS_READ|SYMBOLIC_LINK_QUERY,
  35         STANDARD_RIGHTS_WRITE,
  36         STANDARD_RIGHTS_EXECUTE|SYMBOLIC_LINK_QUERY,
  37         SYMBOLIC_LINK_ALL_ACCESS};
  38
  39 #define TAG_SYMLINK_TTARGET     TAG('S', 'Y', 'T', 'T')
  40 #define TAG_SYMLINK_TARGET      TAG('S', 'Y', 'M', 'T')
  41
  42 /* FUNCTIONS *****************************************************************/
  43
  44
  45 /**********************************************************************
  46  * NAME                                                 INTERNAL
  47  *      IopCreateSymbolicLink
  48  *
  49  * DESCRIPTION
  50  *
  51  * ARGUMENTS
  52  *
  53  * RETURNN VALUE
  54  *      Status.
  55  *
  56  * REVISIONS
  57  */
  58 NTSTATUS STDCALL
  59 IopCreateSymbolicLink(PVOID Object,
  60                       PVOID Parent,
  61                       PWSTR RemainingPath,
  62                       POBJECT_ATTRIBUTES ObjectAttributes)
  63 {
  64   return(STATUS_SUCCESS);
  65 }
  66
  67
  68 /**********************************************************************
  69  * NAME                                                 INTERNAL
  70  *      IopParseSymbolicLink
  71  *
  72  * DESCRIPTION
  73  *
  74  * ARGUMENTS
  75  *
  76  * RETURN VALUE
  77  *
  78  * REVISIONS
  79  */
  80 NTSTATUS STDCALL
  81 IopParseSymbolicLink(PVOID Object,
  82                      PVOID * NextObject,
  83                      PUNICODE_STRING FullPath,
  84                      PWSTR * RemainingPath,
  85                      POBJECT_TYPE ObjectType,
  86                      ULONG Attributes)
  87 {
  88    NTSTATUS Status;
  89    PSYMLNK_OBJECT SymlinkObject = (PSYMLNK_OBJECT) Object;
  90    PVOID ReturnedObject;
  91    UNICODE_STRING TargetPath;
  92
  93    DPRINT("IopParseSymbolicLink (RemainingPath %S)\n", *RemainingPath);
  94    /*
  95     * Stop parsing if the entire path has been parsed and
  96     * the desired object is a symbolic link object.
  97     */
  98    if (((*RemainingPath == NULL) || (**RemainingPath == 0)) &&
  99        (ObjectType == IoSymbolicLinkType))
 100      {
 101         DPRINT("Parsing stopped!\n");
 102         *NextObject = NULL;
 103         return STATUS_SUCCESS;
 104      }
 105
 106    Status = ObReferenceObjectByName(SymlinkObject->Target.ObjectName,
 107                                     0,
 108                                     NULL,
 109                                     STANDARD_RIGHTS_REQUIRED,
 110                                     NULL,
 111                                     UserMode,
 112                                     NULL,
 113                                     &ReturnedObject);
 114    if (NT_SUCCESS(Status))
 115      {
 116         *NextObject = ReturnedObject;
 117         return STATUS_SUCCESS;
 118      }
 119
 120    /* build the expanded path */
 121    TargetPath.MaximumLength = SymlinkObject->TargetName.Length + sizeof(WCHAR);
 122    if (RemainingPath && *RemainingPath)
 123      {
 124         TargetPath.MaximumLength += (wcslen(*RemainingPath) * sizeof(WCHAR));
 125      }
 126    TargetPath.Length = TargetPath.MaximumLength - sizeof(WCHAR);
 127    TargetPath.Buffer = ExAllocatePoolWithTag(NonPagedPool,
 128                                              TargetPath.MaximumLength,
 129                                              TAG_SYMLINK_TTARGET);
 130    wcscpy(TargetPath.Buffer, SymlinkObject->TargetName.Buffer);
 131    if (RemainingPath && *RemainingPath)
 132      {
 133         wcscat(TargetPath.Buffer, *RemainingPath);
 134      }
 135
 136    /* transfer target path buffer into FullPath */
 137    RtlFreeUnicodeString(FullPath);
 138    FullPath->Length = TargetPath.Length;
 139    FullPath->MaximumLength = TargetPath.MaximumLength;
 140    FullPath->Buffer = TargetPath.Buffer;
 141
 142    /* reinitialize RemainingPath for reparsing */
 143    *RemainingPath = FullPath->Buffer;
 144
 145    *NextObject = NULL;
 146    return STATUS_REPARSE;
 147 }
 148
 149 /**********************************************************************
 150  * NAME                                                 INTERNAL
 151  *      IoInitSymbolicLinkImplementation
 152  *
 153  * DESCRIPTION
 154  *
 155  * ARGUMENTS
 156  *      None.
 157  *
 158  * RETURNN VALUE
 159  *      None.
 160  *
 161  * REVISIONS
 162  */
 163 VOID IoInitSymbolicLinkImplementation (VOID)
 164 {
 165    IoSymbolicLinkType = ExAllocatePool(NonPagedPool, sizeof(OBJECT_TYPE));
 166
 167    IoSymbolicLinkType->Tag = TAG('S', 'Y', 'M', 'T');
 168    IoSymbolicLinkType->TotalObjects = 0;
 169    IoSymbolicLinkType->TotalHandles = 0;
 170    IoSymbolicLinkType->MaxObjects = ULONG_MAX;
 171    IoSymbolicLinkType->MaxHandles = ULONG_MAX;
 172    IoSymbolicLinkType->PagedPoolCharge = 0;
 173    IoSymbolicLinkType->NonpagedPoolCharge = sizeof (SYMLNK_OBJECT);
 174    IoSymbolicLinkType->Mapping = &IopSymbolicLinkMapping;
 175    IoSymbolicLinkType->Dump = NULL;
 176    IoSymbolicLinkType->Open = NULL;
 177    IoSymbolicLinkType->Close = NULL;
 178    IoSymbolicLinkType->Delete = NULL;
 179    IoSymbolicLinkType->Parse = IopParseSymbolicLink;
 180    IoSymbolicLinkType->Security = NULL;
 181    IoSymbolicLinkType->QueryName = NULL;
 182    IoSymbolicLinkType->OkayToClose = NULL;
 183    IoSymbolicLinkType->Create = IopCreateSymbolicLink;
 184    IoSymbolicLinkType->DuplicationNotify = NULL;
 185
 186    RtlInitUnicodeString(&IoSymbolicLinkType->TypeName,
 187                         L"SymbolicLink");
 188 }
 189
 190
 191 /**********************************************************************
 192  * NAME                                                 EXPORTED
 193  *      NtOpenSymbolicLinkObject
 194  *
 195  * DESCRIPTION
 196  *
 197  * ARGUMENTS
 198  *
 199  * RETURN VALUE
 200  *
 201  * REVISIONS
 202  *
 203  */
 204 NTSTATUS STDCALL
 205 NtOpenSymbolicLinkObject(OUT PHANDLE LinkHandle,
 206                          IN ACCESS_MASK DesiredAccess,
 207                          IN POBJECT_ATTRIBUTES ObjectAttributes)
 208 {
 209   DPRINT("NtOpenSymbolicLinkObject (Name %wZ)\n",
 210          ObjectAttributes->ObjectName);
 211
 212   return(ObOpenObjectByName(ObjectAttributes,
 213                             IoSymbolicLinkType,
 214                             NULL,
 215                             UserMode,
 216                             DesiredAccess,
 217                             NULL,
 218                             LinkHandle));
 219 }
 220
 221
 222 /**********************************************************************
 223  * NAME                                                 EXPORTED
 224  *      NtQuerySymbolicLinkObject
 225  *
 226  * DESCRIPTION
 227  *
 228  * ARGUMENTS
 229  *
 230  * RETURN VALUE
 231  *
 232  * REVISIONS
 233  *
 234  */
 235 NTSTATUS STDCALL
 236 NtQuerySymbolicLinkObject(IN HANDLE LinkHandle,
 237                           IN OUT PUNICODE_STRING LinkTarget,
 238                           OUT PULONG ReturnedLength OPTIONAL)
 239 {
 240   PSYMLNK_OBJECT SymlinkObject;
 241   NTSTATUS Status;
 242
 243   Status = ObReferenceObjectByHandle(LinkHandle,
 244                                      SYMBOLIC_LINK_QUERY,
 245                                      IoSymbolicLinkType,
 246                                      UserMode,
 247                                      (PVOID *)&SymlinkObject,
 248                                      NULL);
 249   if (!NT_SUCCESS(Status))
 250     {
 251       return(Status);
 252     }
 253
 254   RtlCopyUnicodeString(LinkTarget,
 255                        SymlinkObject->Target.ObjectName);
 256   if (ReturnedLength != NULL)
 257     {
 258       *ReturnedLength = SymlinkObject->Target.Length;
 259     }
 260   ObDereferenceObject(SymlinkObject);
 261
 262   return(STATUS_SUCCESS);
 263 }
 264
 265
 266 /**********************************************************************
 267  * NAME                                                 EXPORTED
 268  *      IoCreateUnprotectedSymbolicLink
 269  *
 270  * DESCRIPTION
 271  *
 272  * ARGUMENTS
 273  *
 274  * RETURN VALUE
 275  *
 276  * REVISIONS
 277  *
 278  */
 279 NTSTATUS STDCALL
 280 IoCreateUnprotectedSymbolicLink(PUNICODE_STRING SymbolicLinkName,
 281                                 PUNICODE_STRING DeviceName)
 282 {
 283   return(IoCreateSymbolicLink(SymbolicLinkName,
 284                               DeviceName));
 285 }
 286
 287
 288 /**********************************************************************
 289  * NAME                                                 EXPORTED
 290  *      IoCreateSymbolicLink
 291  *
 292  * DESCRIPTION
 293  *
 294  * ARGUMENTS
 295  *
 296  * RETURN VALUE
 297  *
 298  * REVISIONS
 299  *
 300  */
 301 NTSTATUS STDCALL
 302 IoCreateSymbolicLink(PUNICODE_STRING SymbolicLinkName,
 303                      PUNICODE_STRING DeviceName)
 304 {
 305         OBJECT_ATTRIBUTES       ObjectAttributes;
 306         PSYMLNK_OBJECT          SymbolicLink;
 307         NTSTATUS                Status;
 308
 309         assert_irql(PASSIVE_LEVEL);
 310
 311         DPRINT(
 312                 "IoCreateSymbolicLink(SymbolicLinkName %S, DeviceName %S)\n",
 313                 SymbolicLinkName->Buffer,
 314                 DeviceName->Buffer
 315                 );
 316
 317         InitializeObjectAttributes(
 318                 & ObjectAttributes,
 319                 SymbolicLinkName,
 320                 OBJ_PERMANENT,
 321                 NULL,
 322                 NULL
 323                 );
 324         Status = ObCreateObject(
 325                         NULL,
 326                         SYMBOLIC_LINK_ALL_ACCESS,
 327                         & ObjectAttributes,
 328                         IoSymbolicLinkType,
 329                         (PVOID*)&SymbolicLink
 330                         );
 331         if (!NT_SUCCESS(Status))
 332         {
 333                 return(Status);
 334         }
 335         SymbolicLink->TargetName.Length = 0;
 336         SymbolicLink->TargetName.MaximumLength =
 337                 ((wcslen(DeviceName->Buffer) + 1) * sizeof(WCHAR));
 338         SymbolicLink->TargetName.Buffer =
 339                 ExAllocatePoolWithTag(NonPagedPool,
 340                                SymbolicLink->TargetName.MaximumLength,
 341                                TAG_SYMLINK_TARGET);
 342         RtlCopyUnicodeString(
 343                 & (SymbolicLink->TargetName),
 344                 DeviceName
 345                 );
 346
 347         DPRINT("DeviceName %S\n", SymbolicLink->TargetName.Buffer);
 348
 349         InitializeObjectAttributes(
 350                 & (SymbolicLink->Target),
 351                 & (SymbolicLink->TargetName),
 352                 0,
 353                 NULL,
 354                 NULL
 355                 );
 356
 357         DPRINT("%s() = STATUS_SUCCESS\n",__FUNCTION__);
 358         ObDereferenceObject( SymbolicLink );
 359         return STATUS_SUCCESS;
 360 }
 361
 362
 363 /**********************************************************************
 364  * NAME                                                 EXPORTED
 365  *      IoDeleteSymbolicLink
 366  *
 367  * DESCRIPTION
 368  *
 369  * ARGUMENTS
 370  *
 371  * RETURN VALUE
 372  *
 373  * REVISIONS
 374  *
 375  */
 376 NTSTATUS STDCALL
 377 IoDeleteSymbolicLink(PUNICODE_STRING SymbolicLinkName)
 378 {
 379         OBJECT_ATTRIBUTES       ObjectAttributes;
 380         HANDLE                  Handle;
 381         NTSTATUS                Status;
 382
 383         assert_irql(PASSIVE_LEVEL);
 384
 385         DPRINT("IoDeleteSymbolicLink (SymbolicLinkName %S)\n",
 386                SymbolicLinkName->Buffer);
 387
 388         InitializeObjectAttributes (&ObjectAttributes,
 389                                     SymbolicLinkName,
 390                                     0,
 391                                     NULL,
 392                                     NULL);
 393
 394         Status = NtOpenSymbolicLinkObject (&Handle,
 395                                            SYMBOLIC_LINK_ALL_ACCESS,
 396                                            &ObjectAttributes);
 397         if (!NT_SUCCESS(Status))
 398                 return Status;
 399
 400         Status = NtMakeTemporaryObject (Handle);
 401         NtClose (Handle);
 402
 403         return Status;
 404 }
 405
 406
 407 /**********************************************************************
 408  * NAME                                         (EXPORTED as Zw)
 409  *      NtCreateSymbolicLinkObject
 410  *
 411  * DESCRIPTION
 412  *
 413  * ARGUMENTS
 414  *
 415  * RETURN VALUE
 416  *
 417  * REVISIONS
 418  *
 419  */
 420 NTSTATUS STDCALL
 421 NtCreateSymbolicLinkObject(OUT PHANDLE SymbolicLinkHandle,
 422                            IN ACCESS_MASK DesiredAccess,
 423                            IN POBJECT_ATTRIBUTES ObjectAttributes,
 424                            IN PUNICODE_STRING DeviceName)
 425 {
 426    PSYMLNK_OBJECT SymbolicLink;
 427    NTSTATUS Status;
 428
 429    assert_irql(PASSIVE_LEVEL);
 430
 431    DPRINT("NtCreateSymbolicLinkObject(SymbolicLinkHandle %p, DesiredAccess %ul, ObjectAttributes %p, DeviceName %S)\n",
 432           SymbolicLinkHandle,
 433           DesiredAccess,
 434           ObjectAttributes,
 435           DeviceName->Buffer);
 436
 437    Status = ObCreateObject(SymbolicLinkHandle,
 438                            DesiredAccess,
 439                            ObjectAttributes,
 440                            IoSymbolicLinkType,
 441                            (PVOID*)&SymbolicLink);
 442    if (!NT_SUCCESS(Status))
 443      {
 444         return(Status);
 445      }
 446
 447    SymbolicLink->TargetName.Length = 0;
 448    SymbolicLink->TargetName.MaximumLength =
 449      ((wcslen(DeviceName->Buffer) + 1) * sizeof(WCHAR));
 450    SymbolicLink->TargetName.Buffer =
 451      ExAllocatePoolWithTag(NonPagedPool,
 452                            SymbolicLink->TargetName.MaximumLength,
 453                            TAG_SYMLINK_TARGET);
 454    RtlCopyUnicodeString(&SymbolicLink->TargetName,
 455                         DeviceName);
 456
 457    DPRINT("DeviceName %S\n", SymbolicLink->TargetName.Buffer);
 458
 459    InitializeObjectAttributes(&SymbolicLink->Target,
 460                               &SymbolicLink->TargetName,
 461                               0,
 462                               NULL,
 463                               NULL);
 464
 465    DPRINT("%s() = STATUS_SUCCESS\n",__FUNCTION__);
 466    ObDereferenceObject(SymbolicLink);
 467    return(STATUS_SUCCESS);
 468 }
 469
 470 /* EOF */