Re: [ros-dev] [ros-diffs] [hbelusca] 57504: [NTOSKRNL] Rearrange the NtQuerySystemEnvironmentValue code to have successive logical checks.

[Timo Kreuzer]

This changes the logic. I'm not sure how exact the previous version was, 
but these changes should be tested.

Am 06.10.2012 21:50, schrieb [e-mail]:
> Author: hbelusca
> Date: Sat Oct  6 19:50:17 2012
> New Revision: 57504
>
> URL: http://svn.reactos.org/svn/reactos?rev=57504&view=rev
> Log:
> [NTOSKRNL]
> Rearrange the NtQuerySystemEnvironmentValue code to have successive logical checks.
>
> Modified:
>      trunk/reactos/ntoskrnl/ex/sysinfo.c
>
> Modified: trunk/reactos/ntoskrnl/ex/sysinfo.c
> URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ex/sysinfo.c?rev=5...
> ==============================================================================
> --- trunk/reactos/ntoskrnl/ex/sysinfo.c [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/ex/sysinfo.c [iso-8859-1] Sat Oct  6 19:50:17 2012
> @@ -235,44 +235,40 @@
>               _SEH2_YIELD(return _SEH2_GetExceptionCode());
>           }
>           _SEH2_END;
> }
> /* Allocate a buffer for the value */
> AnsiValueBuffer = ExAllocatePoolWithTag(NonPagedPool, ValueBufferLength, 'pmeT');
> if (AnsiValueBuffer == NULL)
> {
>    return STATUS_INSUFFICIENT_RESOURCES;
> }
> /*
> * Copy the name to kernel space if necessary and convert it to ANSI.
> */
> }
> /* According to NTInternals the SeSystemEnvironmentName privilege is required! */
> if (!SeSinglePrivilegeCheck(SeSystemEnvironmentPrivilege, PreviousMode))
> {
>    DPRINT1("NtQuerySystemEnvironmentValue: Caller requires the SeSystemEnvironmentPrivilege privilege!\n");
>    return STATUS_PRIVILEGE_NOT_HELD;
> }
> /* Copy the name to kernel space if necessary */
>  Status = ProbeAndCaptureUnicodeString(&WName, PreviousMode, VariableName);
>  if (!NT_SUCCESS(Status))
>  {
>      return Status;
>  }
> /*
> * according to ntinternals the SeSystemEnvironmentName privilege is required!
> */
> if (!SeSinglePrivilegeCheck(SeSystemEnvironmentPrivilege, PreviousMode))
> {
>    ReleaseCapturedUnicodeString(&WName, PreviousMode);
>    DPRINT1("NtQuerySystemEnvironmentValue: Caller requires the SeSystemEnvironmentPrivilege privilege!\n");
>    return STATUS_PRIVILEGE_NOT_HELD;
> }
> /* Convert the value name to ansi and release the captured unicode string */
> /* Convert the name to ANSI and release the captured UNICODE string */
>  Status = RtlUnicodeStringToAnsiString(&AName, &WName, TRUE);
>  ReleaseCapturedUnicodeString(&WName, PreviousMode);
>  if (!NT_SUCCESS(Status)) return Status;
> /* Get the environment variable */
>
> /* Allocate a buffer for the ANSI environment variable */
>
> AnsiValueBuffer = ExAllocatePoolWithTag(NonPagedPool, ValueBufferLength, 'pmeT');
>
> if (AnsiValueBuffer == NULL)
>
> {
>    RtlFreeAnsiString(&AName);
>    return STATUS_INSUFFICIENT_RESOURCES;
>
> }
>
> /* Get the environment variable and free the ANSI name */
>  Result = HalGetEnvironmentVariable(AName.Buffer,
>                                     (USHORT)ValueBufferLength,
>                                     AnsiValueBuffer);
>
> RtlFreeAnsiString(&AName);
>
> /* Check if we had success */
>  if (Result == ESUCCESS)
>
> @@ -280,13 +276,13 @@
>           /* Copy the result back to the caller. */
>           _SEH2_TRY
>           {
>        /* Initialize ansi string from the result */
>        /* Initialize ANSI string from the result */
>         RtlInitAnsiString(&AValue, AnsiValueBuffer);
>
>        /* Initialize a unicode string from the callers buffer */
>        /* Initialize a UNICODE string from the callers buffer */
>         RtlInitEmptyUnicodeString(&WValue, ValueBuffer, ValueBufferLength);
>
>        /* Convert the result to unicode */
>        /* Convert the result to UNICODE */
>         Status = RtlAnsiStringToUnicodeString(&WValue, &AValue, FALSE);
>
>         if (ReturnLength != NULL)
>
> @@ -305,8 +301,7 @@
>           Status = STATUS_UNSUCCESSFUL;
>       }
> /* Cleanup allocated resources. */
> RtlFreeAnsiString(&AName);
>
> /* Free the allocated ANSI value buffer */
>  ExFreePoolWithTag(AnsiValueBuffer, 'pmeT');
>
> return Status;