reactos/win32ss/user/ntuser/useratom.c

   1 /*
   2  * COPYRIGHT:        See COPYING in the top level directory
   3  * PROJECT:          ReactOS kernel
   4  * PURPOSE:          User Atom helper routines
   5  * FILE:             win32ss/user/ntuser/useratom.c
   6  * PROGRAMER:        Filip Navara <xnavara@volny.cz>
   7  */
   8
   9 #include <win32k.h>
  10 DBG_DEFAULT_CHANNEL(UserMisc);
  11
  12 RTL_ATOM FASTCALL
  13 IntAddAtom(LPWSTR AtomName)
  14 {
  15     NTSTATUS Status = STATUS_SUCCESS;
  16     PTHREADINFO pti;
  17     RTL_ATOM Atom;
  18
  19     pti = PsGetCurrentThreadWin32Thread();
  20     if (pti->rpdesk == NULL)
  21     {
  22         SetLastNtError(Status);
  23         return (RTL_ATOM)0;
  24     }
  25
  26     Status = RtlAddAtomToAtomTable(gAtomTable, AtomName, &Atom);
  27
  28     if (!NT_SUCCESS(Status))
  29     {
  30         SetLastNtError(Status);
  31         return (RTL_ATOM)0;
  32     }
  33     return Atom;
  34 }
  35
  36 ULONG FASTCALL
  37 IntGetAtomName(RTL_ATOM nAtom, LPWSTR lpBuffer, ULONG cjBufSize)
  38 {
  39     NTSTATUS Status = STATUS_SUCCESS;
  40     PTHREADINFO pti;
  41     ULONG Size = cjBufSize;
  42
  43     pti = PsGetCurrentThreadWin32Thread();
  44     if (pti->rpdesk == NULL)
  45     {
  46         SetLastNtError(Status);
  47         return 0;
  48     }
  49
  50     Status = RtlQueryAtomInAtomTable(gAtomTable, nAtom, NULL, NULL, lpBuffer, &Size);
  51
  52     if (!NT_SUCCESS(Status))
  53     {
  54         SetLastNtError(Status);
  55         return 0;
  56     }
  57
  58     return Size;
  59 }
  60
  61 RTL_ATOM FASTCALL
  62 IntAddGlobalAtom(LPWSTR lpBuffer, BOOL PinAtom)
  63 {
  64     RTL_ATOM Atom;
  65     NTSTATUS Status = STATUS_SUCCESS;
  66
  67     Status = RtlAddAtomToAtomTable(gAtomTable, lpBuffer, &Atom);
  68
  69     if (!NT_SUCCESS(Status))
  70     {
  71         ERR("Error init Global Atom.\n");
  72         return 0;
  73     }
  74
  75     if (Atom && PinAtom)
  76         RtlPinAtomInAtomTable(gAtomTable, Atom);
  77
  78     return Atom;
  79 }
  80
  81 /*!
  82  * \brief Returns the name of an atom.
  83  *
  84  * \param atom - The atom to be queried.
  85  * \param pustrName - Pointer to an initialized UNICODE_STRING that receives
  86  *                    the name of the atom. The function does not update the
  87                       Length member. The string is always NULL-terminated.
  88  *
  89  * \return The length of the name in characters, or 0 if the function fails.
  90  *
  91  * \note The function does not aquire any global lock, since synchronisation is
  92  *       handled by the RtlAtom function.
  93  */
  94 _Success_(return != 0)
  95 _At_(pustrName->Buffer, _Out_z_bytecap_post_bytecount_(pustrName->MaximumLength, return * 2 + 2))
  96 ULONG
  97 APIENTRY
  98 NtUserGetAtomName(
  99     _In_ ATOM atom,
 100     _Inout_ PUNICODE_STRING pustrName)
 101 {
 102     WCHAR awcBuffer[256];
 103     ULONG cjLength;
 104
 105     /* Retrieve the atom name into a local buffer (max length is 255 chars) */
 106     cjLength = IntGetAtomName((RTL_ATOM)atom, awcBuffer, sizeof(awcBuffer));
 107     if (cjLength != 0)
 108     {
 109         _SEH2_TRY
 110         {
 111             /* Probe the unicode string and the buffer */
 112             ProbeForRead(pustrName, sizeof(*pustrName), 1);
 113             ProbeForWrite(pustrName->Buffer, pustrName->MaximumLength, 1);
 114
 115             /* Check if we have enough space to write the NULL termination */
 116             if (pustrName->MaximumLength >= sizeof(UNICODE_NULL))
 117             {
 118                 /* Limit the length to the buffer size */
 119                 cjLength = min(pustrName->MaximumLength - sizeof(UNICODE_NULL),
 120                                cjLength);
 121
 122                 /* Copy the string and NULL terminate it */
 123                 RtlCopyMemory(pustrName->Buffer, awcBuffer, cjLength);
 124                 pustrName->Buffer[cjLength / sizeof(WCHAR)] = L'\0';
 125             }
 126             else
 127             {
 128                 cjLength = 0;
 129             }
 130         }
 131         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 132         {
 133             /* On exception, set last error and fail */
 134             SetLastNtError(_SEH2_GetExceptionCode());
 135             cjLength = 0;
 136         }
 137         _SEH2_END
 138     }
 139
 140     /* Return the length in characters */
 141     return cjLength / sizeof(WCHAR);
 142 }
 143
 144 /* EOF */