reactos/drivers/filesystems/npfs_new/prefxsup.c

   1 /*
   2  * PROJECT:     ReactOS Named Pipe FileSystem
   3  * LICENSE:     BSD - See COPYING.ARM in the top level directory
   4  * FILE:        drivers/filesystems/npfs/prefxsup.c
   5  * PURPOSE:     Pipes Prefixes Support
   6  * PROGRAMMERS: ReactOS Portable Systems Group
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #include "npfs.h"
  12
  13 /* FUNCTIONS ******************************************************************/
  14
  15 PNP_FCB
  16 NTAPI
  17 NpFindPrefix(IN PUNICODE_STRING Name,
  18              IN ULONG CaseInsensitiveIndex,
  19              IN PUNICODE_STRING Prefix)
  20 {
  21     PUNICODE_PREFIX_TABLE_ENTRY Entry;
  22     PNP_FCB Fcb;
  23     PAGED_CODE();
  24
  25     Entry = RtlFindUnicodePrefix(&NpVcb->PrefixTable,
  26                                  Name,
  27                                  CaseInsensitiveIndex);
  28     if (!Entry) KeBugCheckEx(NPFS_FILE_SYSTEM, 0x100065u, 0, 0, 0);
  29
  30     Fcb = CONTAINING_RECORD(Entry, NP_FCB, PrefixTableEntry);
  31
  32     Prefix->Length = Name->Length - Fcb->FullName.Length;
  33     Prefix->MaximumLength = Prefix->Length;
  34     Prefix->Buffer = &Name->Buffer[Fcb->FullName.Length / sizeof(WCHAR)];
  35
  36     if ((Prefix->Length) && (Prefix->Buffer[0] == OBJ_NAME_PATH_SEPARATOR))
  37     {
  38         Prefix->Length -= sizeof(WCHAR);
  39         Prefix->MaximumLength -= sizeof(WCHAR);
  40         ++Prefix->Buffer;
  41     }
  42
  43     return Fcb;
  44 }
  45
  46 NTSTATUS
  47 NTAPI
  48 NpFindRelativePrefix(IN PNP_DCB Dcb,
  49                      IN PUNICODE_STRING Name,
  50                      IN ULONG CaseInsensitiveIndex,
  51                      IN PUNICODE_STRING Prefix,
  52                      OUT PNP_FCB *FoundFcb)
  53 {
  54     PWCHAR Buffer;
  55     PNP_FCB Fcb;
  56     UNICODE_STRING RootName;
  57     USHORT Length, MaximumLength;
  58     PAGED_CODE();
  59
  60     Length = Name->Length;
  61     MaximumLength = Length + sizeof(OBJ_NAME_PATH_SEPARATOR) + sizeof(UNICODE_NULL);
  62     if (MaximumLength < Length) return STATUS_INVALID_PARAMETER;
  63
  64     ASSERT(Dcb->NodeType == NPFS_NTC_ROOT_DCB);
  65
  66     Buffer = ExAllocatePoolWithTag(PagedPool, MaximumLength, NPFS_NAME_BLOCK_TAG);
  67     if (!Buffer)
  68     {
  69         return STATUS_INSUFFICIENT_RESOURCES;
  70     }
  71
  72     *Buffer = OBJ_NAME_PATH_SEPARATOR;
  73     RtlCopyMemory(Buffer + 1, Name->Buffer, Length);
  74     Buffer[(Length / sizeof(WCHAR)) + 1] = UNICODE_NULL;
  75
  76     RootName.Length = Length + sizeof(OBJ_NAME_PATH_SEPARATOR);
  77     RootName.MaximumLength = MaximumLength;
  78     RootName.Buffer = Buffer;
  79
  80     Fcb = NpFindPrefix(&RootName, CaseInsensitiveIndex, Prefix);
  81
  82     ExFreePool(Buffer);
  83
  84     Prefix->Buffer = &Name->Buffer[(Length - Prefix->Length) / sizeof(WCHAR)];
  85     *FoundFcb = Fcb;
  86
  87     return STATUS_SUCCESS;
  88 }
  89
  90 /* EOF */