fltlib.c File Reference

#include <stdarg.h>
#include <windef.h>
#include <winbase.h>
#include <ndk/iofuncs.h>
#include <ndk/obfuncs.h>
#include <ndk/rtlfuncs.h>
#include <fltmgr_shared.h>

Include dependency graph for fltlib.c:

Go to the source code of this file.

Macros
#define	WIN32_NO_STATUS
#define	NTOS_MODE_USER

Functions
static HRESULT	FilterLoadUnload (_In_z_ LPCWSTR lpFilterName, _In_ BOOL Load)
static DWORD	SendIoctl (_In_ HANDLE Handle, _In_ ULONG IoControlCode, _In_reads_bytes_opt_(BufferSize) LPVOID lpInBuffer, _In_ DWORD BufferSize)
_Must_inspect_result_ HRESULT WINAPI	FilterLoad (_In_ LPCWSTR lpFilterName)
_Must_inspect_result_ HRESULT WINAPI	FilterUnload (_In_ LPCWSTR lpFilterName)
HRESULT	NtStatusToHResult (_In_ NTSTATUS Status)
BOOL WINAPI	DllMain (_In_ HINSTANCE hinstDLL, _In_ DWORD dwReason, _In_ LPVOID lpvReserved)

Macro Definition Documentation

NTOS_MODE_USER

#define NTOS_MODE_USER

Definition at line 16 of file fltlib.c.

WIN32_NO_STATUS

#define WIN32_NO_STATUS

Definition at line 11 of file fltlib.c.

Function Documentation

DllMain()

BOOL WINAPI DllMain	(	_In_ HINSTANCE	hinstDLL,
		_In_ DWORD	dwReason,
		_In_ LPVOID	lpvReserved
	)

Definition at line 158 of file fltlib.c.

{
    switch (dwReason)
    {
    case DLL_PROCESS_ATTACH:
        DisableThreadLibraryCalls(hinstDLL);
        break;
    }
 
    return TRUE;
}

FilterLoad()

_Must_inspect_result_ HRESULT WINAPI FilterLoad

(

_In_ LPCWSTR

lpFilterName

)

Definition at line 42 of file fltlib.c.

{
    return FilterLoadUnload(lpFilterName, TRUE);
}

Referenced by KmtFltLoad(), and LoadFilter().

FilterLoadUnload()

static HRESULT FilterLoadUnload ( _In_z_ LPCWSTR  lpFilterName, _In_ BOOL  Load  )

static

Definition at line 72 of file fltlib.c.

{
    PFILTER_NAME FilterName;
    HANDLE hFltMgr;
    SIZE_T StringLength;
    SIZE_T BufferLength;
    DWORD dwError;
 
    /* Get a handle to the filter manager */
    hFltMgr = CreateFileW(L"\\\\.\\fltmgr",
                          GENERIC_WRITE,
                          FILE_SHARE_WRITE,
                          NULL,
                          OPEN_EXISTING,
                          FILE_ATTRIBUTE_NORMAL,
                          &hFltMgr);
    if (hFltMgr == INVALID_HANDLE_VALUE)
    {
        dwError = GetLastError();
        return HRESULT_FROM_WIN32(dwError);
    }
 
    /* Calc and allocate a buffer to hold our filter name */
    StringLength = wcslen(lpFilterName) * sizeof(WCHAR);
    BufferLength = StringLength + sizeof(FILTER_NAME);
    FilterName = RtlAllocateHeap(GetProcessHeap(),
                                 0,
                                 BufferLength);
    if (FilterName == NULL)
    {
        CloseHandle(hFltMgr);
        return HRESULT_FROM_WIN32(ERROR_OUTOFMEMORY);
    }
 
    /* Build up the filter name */
    FilterName->Length = StringLength;
    CopyMemory(FilterName->FilterName, lpFilterName, StringLength);
 
    /* Tell the filter manager to load the filter for us */
    dwError = SendIoctl(hFltMgr,
                        Load ? IOCTL_FILTER_LOAD : IOCTL_FILTER_UNLOAD,
                        FilterName,
                        BufferLength);
 
    /* Cleanup and bail*/
    RtlFreeHeap(GetProcessHeap(), 0, FilterName);
    CloseHandle(hFltMgr);
 
    return HRESULT_FROM_WIN32(dwError);
}

Referenced by FilterLoad(), and FilterUnload().

FilterUnload()

_Must_inspect_result_ HRESULT WINAPI FilterUnload

(

_In_ LPCWSTR

lpFilterName

)

Definition at line 50 of file fltlib.c.

{
    return FilterLoadUnload(lpFilterName, FALSE);
}

Referenced by KmtFltUnload(), and UnloadFilter().

NtStatusToHResult()

HRESULT NtStatusToHResult

(

_In_ NTSTATUS

Status

)

Definition at line 59 of file fltlib.c.

{
    HRESULT hr;
    hr = RtlNtStatusToDosError(Status);
    if (hr != ERROR_SUCCESS)
    {
        hr = (ULONG)hr | 0x80070000;
    }
    return hr;
}

Referenced by FilterConnectCommunicationPort().

SendIoctl()

static DWORD SendIoctl ( _In_ HANDLE  Handle, _In_ ULONG  IoControlCode, _In_reads_bytes_opt_(BufferSize) LPVOID  lpInBuffer, _In_ DWORD  BufferSize  )

static

Definition at line 126 of file fltlib.c.

{
    IO_STATUS_BLOCK IoStatusBlock;
    NTSTATUS Status;
 
    Status = NtDeviceIoControlFile(Handle,
                                   NULL,
                                   NULL,
                                   NULL,
                                   &IoStatusBlock,
                                   IoControlCode,
                                   lpInBuffer,
                                   BufferSize,
                                   NULL,
                                   0);
    if (Status == STATUS_PENDING)
    {
        Status = NtWaitForSingleObject(Handle, FALSE, NULL);
        if (NT_SUCCESS(Status))
        {
            Status = IoStatusBlock.Status;
        }
    }
 
    return RtlNtStatusToDosError(Status);
}

Referenced by FilterLoadUnload().