reactos/drivers/filesystems/npfs/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 // File ID number for NPFS bugchecking support
  14 #define NPFS_BUGCHECK_FILE_ID   (NPFS_BUGCHECK_PREFXSUP)
  15
  16 /* FUNCTIONS ******************************************************************/
  17
  18 PNP_FCB
  19 NTAPI
  20 NpFindPrefix(IN PUNICODE_STRING Name,
  21              IN ULONG CaseInsensitiveIndex,
  22              IN PUNICODE_STRING Prefix)
  23 {
  24     PUNICODE_PREFIX_TABLE_ENTRY Entry;
  25     PNP_FCB Fcb;
  26     PAGED_CODE();
  27
  28     Entry = RtlFindUnicodePrefix(&NpVcb->PrefixTable,
  29                                  Name,
  30                                  CaseInsensitiveIndex);
  31     if (!Entry) NpBugCheck(0, 0, 0);
  32
  33     Fcb = CONTAINING_RECORD(Entry, NP_FCB, PrefixTableEntry);
  34
  35     Prefix->Length = Name->Length - Fcb->FullName.Length;
  36     Prefix->MaximumLength = Prefix->Length;
  37     Prefix->Buffer = &Name->Buffer[Fcb->FullName.Length / sizeof(WCHAR)];
  38
  39     if ((Prefix->Length) && (Prefix->Buffer[0] == OBJ_NAME_PATH_SEPARATOR))
  40     {
  41         Prefix->Length -= sizeof(WCHAR);
  42         Prefix->MaximumLength -= sizeof(WCHAR);
  43         ++Prefix->Buffer;
  44     }
  45
  46     return Fcb;
  47 }
  48
  49 NTSTATUS
  50 NTAPI
  51 NpFindRelativePrefix(IN PNP_DCB Dcb,
  52                      IN PUNICODE_STRING Name,
  53                      IN ULONG CaseInsensitiveIndex,
  54                      IN PUNICODE_STRING Prefix,
  55                      OUT PNP_FCB *FoundFcb)
  56 {
  57     PWCHAR Buffer;
  58     PNP_FCB Fcb;
  59     UNICODE_STRING RootName;
  60     USHORT Length, MaximumLength;
  61     PAGED_CODE();
  62
  63     Length = Name->Length;
  64     MaximumLength = Length + sizeof(OBJ_NAME_PATH_SEPARATOR) + sizeof(UNICODE_NULL);
  65     if (MaximumLength < Length) return STATUS_INVALID_PARAMETER;
  66
  67     ASSERT(Dcb->NodeType == NPFS_NTC_ROOT_DCB);
  68
  69     Buffer = ExAllocatePoolWithTag(PagedPool, MaximumLength, NPFS_NAME_BLOCK_TAG);
  70     if (!Buffer)
  71     {
  72         return STATUS_INSUFFICIENT_RESOURCES;
  73     }
  74
  75     *Buffer = OBJ_NAME_PATH_SEPARATOR;
  76     RtlCopyMemory(Buffer + 1, Name->Buffer, Length);
  77     Buffer[(Length / sizeof(WCHAR)) + 1] = UNICODE_NULL;
  78
  79     RootName.Length = Length + sizeof(OBJ_NAME_PATH_SEPARATOR);
  80     RootName.MaximumLength = MaximumLength;
  81     RootName.Buffer = Buffer;
  82
  83     Fcb = NpFindPrefix(&RootName, CaseInsensitiveIndex, Prefix);
  84
  85     ExFreePool(Buffer);
  86
  87     Prefix->Buffer = &Name->Buffer[(Length - Prefix->Length) / sizeof(WCHAR)];
  88     *FoundFcb = Fcb;
  89
  90     return STATUS_SUCCESS;
  91 }
  92
  93 /* EOF */