ntoskrnl/io/symlink.c

   1 /* $Id$
   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                      ULONG Attributes)
  86 {
  87    PSYMLNK_OBJECT SymlinkObject = (PSYMLNK_OBJECT) Object;
  88    UNICODE_STRING TargetPath;
  89
  90    DPRINT("IopParseSymbolicLink (RemainingPath %S)\n", *RemainingPath);
  91    /*
  92     * Stop parsing if the entire path has been parsed and
  93     * the desired object is a symbolic link object.
  94     */
  95    if (((*RemainingPath == NULL) || (**RemainingPath == 0)) &&
  96        (Attributes & OBJ_OPENLINK))
  97      {
  98         DPRINT("Parsing stopped!\n");
  99         *NextObject = NULL;
 100         return STATUS_SUCCESS;
 101      }
 102
 103    /* build the expanded path */
 104    TargetPath.MaximumLength = SymlinkObject->TargetName.Length + sizeof(WCHAR);
 105    if (RemainingPath && *RemainingPath)
 106      {
 107         TargetPath.MaximumLength += (wcslen(*RemainingPath) * sizeof(WCHAR));
 108      }
 109    TargetPath.Length = TargetPath.MaximumLength - sizeof(WCHAR);
 110    TargetPath.Buffer = ExAllocatePoolWithTag(NonPagedPool,
 111                                              TargetPath.MaximumLength,
 112                                              TAG_SYMLINK_TTARGET);
 113    wcscpy(TargetPath.Buffer, SymlinkObject->TargetName.Buffer);
 114    if (RemainingPath && *RemainingPath)
 115      {
 116         wcscat(TargetPath.Buffer, *RemainingPath);
 117      }
 118
 119    /* transfer target path buffer into FullPath */
 120    RtlFreeUnicodeString(FullPath);
 121    FullPath->Length = TargetPath.Length;
 122    FullPath->MaximumLength = TargetPath.MaximumLength;
 123    FullPath->Buffer = TargetPath.Buffer;
 124
 125    /* reinitialize RemainingPath for reparsing */
 126    *RemainingPath = FullPath->Buffer;
 127
 128    *NextObject = NULL;
 129    return STATUS_REPARSE;
 130 }
 131
 132 /**********************************************************************
 133  * NAME                                                 INTERNAL
 134  *      IoInitSymbolicLinkImplementation
 135  *
 136  * DESCRIPTION
 137  *
 138  * ARGUMENTS
 139  *      None.
 140  *
 141  * RETURNN VALUE
 142  *      None.
 143  *
 144  * REVISIONS
 145  */
 146 VOID IoInitSymbolicLinkImplementation (VOID)
 147 {
 148    IoSymbolicLinkType = ExAllocatePool(NonPagedPool, sizeof(OBJECT_TYPE));
 149
 150    IoSymbolicLinkType->Tag = TAG('S', 'Y', 'M', 'T');
 151    IoSymbolicLinkType->TotalObjects = 0;
 152    IoSymbolicLinkType->TotalHandles = 0;
 153    IoSymbolicLinkType->MaxObjects = ULONG_MAX;
 154    IoSymbolicLinkType->MaxHandles = ULONG_MAX;
 155    IoSymbolicLinkType->PagedPoolCharge = 0;
 156    IoSymbolicLinkType->NonpagedPoolCharge = sizeof (SYMLNK_OBJECT);
 157    IoSymbolicLinkType->Mapping = &IopSymbolicLinkMapping;
 158    IoSymbolicLinkType->Dump = NULL;
 159    IoSymbolicLinkType->Open = NULL;
 160    IoSymbolicLinkType->Close = NULL;
 161    IoSymbolicLinkType->Delete = NULL;
 162    IoSymbolicLinkType->Parse = IopParseSymbolicLink;
 163    IoSymbolicLinkType->Security = NULL;
 164    IoSymbolicLinkType->QueryName = NULL;
 165    IoSymbolicLinkType->OkayToClose = NULL;
 166    IoSymbolicLinkType->Create = IopCreateSymbolicLink;
 167    IoSymbolicLinkType->DuplicationNotify = NULL;
 168
 169    RtlInitUnicodeStringFromLiteral(&IoSymbolicLinkType->TypeName,
 170                         L"SymbolicLink");
 171 }
 172
 173
 174 /**********************************************************************
 175  * NAME                                                 EXPORTED
 176  *      NtOpenSymbolicLinkObject
 177  *
 178  * DESCRIPTION
 179  *
 180  * ARGUMENTS
 181  *
 182  * RETURN VALUE
 183  *
 184  * REVISIONS
 185  *
 186  */
 187 NTSTATUS STDCALL
 188 NtOpenSymbolicLinkObject(OUT PHANDLE LinkHandle,
 189                          IN ACCESS_MASK DesiredAccess,
 190                          IN POBJECT_ATTRIBUTES ObjectAttributes)
 191 {
 192   DPRINT("NtOpenSymbolicLinkObject (Name %wZ)\n",
 193          ObjectAttributes->ObjectName);
 194
 195   return(ObOpenObjectByName(ObjectAttributes,
 196                             IoSymbolicLinkType,
 197                             NULL,
 198                             UserMode,
 199                             DesiredAccess,
 200                             NULL,
 201                             LinkHandle));
 202 }
 203
 204
 205 /**********************************************************************
 206  * NAME                                                 EXPORTED
 207  *      NtQuerySymbolicLinkObject
 208  *
 209  * DESCRIPTION
 210  *
 211  * ARGUMENTS
 212  *
 213  * RETURN VALUE
 214  *
 215  * REVISIONS
 216  *
 217  */
 218 NTSTATUS STDCALL
 219 NtQuerySymbolicLinkObject(IN HANDLE LinkHandle,
 220                           IN OUT PUNICODE_STRING LinkTarget,
 221                           OUT PULONG ReturnedLength OPTIONAL)
 222 {
 223   PSYMLNK_OBJECT SymlinkObject;
 224   NTSTATUS Status;
 225
 226   Status = ObReferenceObjectByHandle(LinkHandle,
 227                                      SYMBOLIC_LINK_QUERY,
 228                                      IoSymbolicLinkType,
 229                                      UserMode,
 230                                      (PVOID *)&SymlinkObject,
 231                                      NULL);
 232   if (!NT_SUCCESS(Status))
 233     {
 234       return(Status);
 235     }
 236
 237   RtlCopyUnicodeString(LinkTarget,
 238                        SymlinkObject->Target.ObjectName);
 239   if (ReturnedLength != NULL)
 240     {
 241       *ReturnedLength = SymlinkObject->Target.Length;
 242     }
 243   ObDereferenceObject(SymlinkObject);
 244
 245   return(STATUS_SUCCESS);
 246 }
 247
 248
 249 /**********************************************************************
 250  * NAME                                                 EXPORTED
 251  *      IoCreateUnprotectedSymbolicLink
 252  *
 253  * DESCRIPTION
 254  *
 255  * ARGUMENTS
 256  *
 257  * RETURN VALUE
 258  *
 259  * REVISIONS
 260  *
 261  */
 262 NTSTATUS STDCALL
 263 IoCreateUnprotectedSymbolicLink(PUNICODE_STRING SymbolicLinkName,
 264                                 PUNICODE_STRING DeviceName)
 265 {
 266   return(IoCreateSymbolicLink(SymbolicLinkName,
 267                               DeviceName));
 268 }
 269
 270
 271 /**********************************************************************
 272  * NAME                                                 EXPORTED
 273  *      IoCreateSymbolicLink
 274  *
 275  * DESCRIPTION
 276  *
 277  * ARGUMENTS
 278  *
 279  * RETURN VALUE
 280  *
 281  * REVISIONS
 282  *
 283  */
 284 NTSTATUS STDCALL
 285 IoCreateSymbolicLink(PUNICODE_STRING SymbolicLinkName,
 286                      PUNICODE_STRING DeviceName)
 287 {
 288         OBJECT_ATTRIBUTES       ObjectAttributes;
 289         PSYMLNK_OBJECT          SymbolicLink;
 290         NTSTATUS                Status;
 291
 292         assert_irql(PASSIVE_LEVEL);
 293
 294         DPRINT(
 295                 "IoCreateSymbolicLink(SymbolicLinkName %S, DeviceName %S)\n",
 296                 SymbolicLinkName->Buffer,
 297                 DeviceName->Buffer
 298                 );
 299
 300         InitializeObjectAttributes(
 301                 & ObjectAttributes,
 302                 SymbolicLinkName,
 303                 OBJ_PERMANENT,
 304                 NULL,
 305                 NULL
 306                 );
 307         Status = ObCreateObject(
 308                         NULL,
 309                         SYMBOLIC_LINK_ALL_ACCESS,
 310                         & ObjectAttributes,
 311                         IoSymbolicLinkType,
 312                         (PVOID*)&SymbolicLink
 313                         );
 314         if (!NT_SUCCESS(Status))
 315         {
 316                 return(Status);
 317         }
 318         SymbolicLink->TargetName.Length = 0;
 319         SymbolicLink->TargetName.MaximumLength =
 320                 ((wcslen(DeviceName->Buffer) + 1) * sizeof(WCHAR));
 321         SymbolicLink->TargetName.Buffer =
 322                 ExAllocatePoolWithTag(NonPagedPool,
 323                                SymbolicLink->TargetName.MaximumLength,
 324                                TAG_SYMLINK_TARGET);
 325         RtlCopyUnicodeString(
 326                 & (SymbolicLink->TargetName),
 327                 DeviceName
 328                 );
 329
 330         DPRINT("DeviceName %S\n", SymbolicLink->TargetName.Buffer);
 331
 332         InitializeObjectAttributes(
 333                 & (SymbolicLink->Target),
 334                 & (SymbolicLink->TargetName),
 335                 0,
 336                 NULL,
 337                 NULL
 338                 );
 339
 340         DPRINT("%s() = STATUS_SUCCESS\n",__FUNCTION__);
 341         ObDereferenceObject( SymbolicLink );
 342         return STATUS_SUCCESS;
 343 }
 344
 345
 346 /**********************************************************************
 347  * NAME                                                 EXPORTED
 348  *      IoDeleteSymbolicLink
 349  *
 350  * DESCRIPTION
 351  *
 352  * ARGUMENTS
 353  *
 354  * RETURN VALUE
 355  *
 356  * REVISIONS
 357  *
 358  */
 359 NTSTATUS STDCALL
 360 IoDeleteSymbolicLink(PUNICODE_STRING SymbolicLinkName)
 361 {
 362   OBJECT_ATTRIBUTES ObjectAttributes;
 363   HANDLE Handle;
 364   NTSTATUS Status;
 365
 366   assert_irql(PASSIVE_LEVEL);
 367
 368   DPRINT("IoDeleteSymbolicLink (SymbolicLinkName %S)\n",
 369          SymbolicLinkName->Buffer);
 370
 371   InitializeObjectAttributes(&ObjectAttributes,
 372                              SymbolicLinkName,
 373                              OBJ_OPENLINK,
 374                              NULL,
 375                              NULL);
 376
 377   Status = NtOpenSymbolicLinkObject(&Handle,
 378                                     SYMBOLIC_LINK_ALL_ACCESS,
 379                                     &ObjectAttributes);
 380   if (!NT_SUCCESS(Status))
 381     return(Status);
 382
 383   Status = NtMakeTemporaryObject(Handle);
 384   NtClose(Handle);
 385
 386   return(Status);
 387 }
 388
 389
 390 /**********************************************************************
 391  * NAME                                         (EXPORTED as Zw)
 392  *      NtCreateSymbolicLinkObject
 393  *
 394  * DESCRIPTION
 395  *
 396  * ARGUMENTS
 397  *
 398  * RETURN VALUE
 399  *
 400  * REVISIONS
 401  *
 402  */
 403 NTSTATUS STDCALL
 404 NtCreateSymbolicLinkObject(OUT PHANDLE SymbolicLinkHandle,
 405                            IN ACCESS_MASK DesiredAccess,
 406                            IN POBJECT_ATTRIBUTES ObjectAttributes,
 407                            IN PUNICODE_STRING DeviceName)
 408 {
 409    PSYMLNK_OBJECT SymbolicLink;
 410    NTSTATUS Status;
 411
 412    assert_irql(PASSIVE_LEVEL);
 413
 414    DPRINT("NtCreateSymbolicLinkObject(SymbolicLinkHandle %p, DesiredAccess %ul, ObjectAttributes %p, DeviceName %S)\n",
 415           SymbolicLinkHandle,
 416           DesiredAccess,
 417           ObjectAttributes,
 418           DeviceName->Buffer);
 419
 420    Status = ObCreateObject(SymbolicLinkHandle,
 421                            DesiredAccess,
 422                            ObjectAttributes,
 423                            IoSymbolicLinkType,
 424                            (PVOID*)&SymbolicLink);
 425    if (!NT_SUCCESS(Status))
 426      {
 427         return(Status);
 428      }
 429
 430    SymbolicLink->TargetName.Length = 0;
 431    SymbolicLink->TargetName.MaximumLength =
 432      ((wcslen(DeviceName->Buffer) + 1) * sizeof(WCHAR));
 433    SymbolicLink->TargetName.Buffer =
 434      ExAllocatePoolWithTag(NonPagedPool,
 435                            SymbolicLink->TargetName.MaximumLength,
 436                            TAG_SYMLINK_TARGET);
 437    RtlCopyUnicodeString(&SymbolicLink->TargetName,
 438                         DeviceName);
 439
 440    DPRINT("DeviceName %S\n", SymbolicLink->TargetName.Buffer);
 441
 442    InitializeObjectAttributes(&SymbolicLink->Target,
 443                               &SymbolicLink->TargetName,
 444                               0,
 445                               NULL,
 446                               NULL);
 447
 448    DPRINT("%s() = STATUS_SUCCESS\n",__FUNCTION__);
 449    ObDereferenceObject(SymbolicLink);
 450    return(STATUS_SUCCESS);
 451 }
 452
 453 /* EOF */