/*++
Copyright (c) 1995 Microsoft Corporation
Module Name:
apc.c
Abstract:
This module implements the APC helper functions for the WinSock 2.0
helper library. This particular implementation is specific to NT 3.51.
Author:
Keith Moore (keithmo) 20-Jun-1995
Revision History:
--*/
#include "precomp.h"
VOID
WINAPI
WahpIntermediateApc(
LPVOID Context,
LPVOID SystemArgument1,
LPVOID SystemArgument2
);
//
// Public functions.
//
DWORD
WINAPI
WahOpenApcHelper(
OUT LPHANDLE HelperHandle
)
/*++
Routine Description:
This routine opens the WinSock 2.0 APC helper device.
Arguments:
HelperHandle - Points to a HANDLE that will receive an open handle
to the APC helper device.
Return Value:
DWORD - NO_ERROR if successful, a Win32 error code if not.
--*/
{
NTSTATUS status;
OBJECT_ATTRIBUTES objectAttributes;
UNICODE_STRING helperName;
IO_STATUS_BLOCK ioStatusBlock;
//
// Validate parameters.
//
if( HelperHandle == NULL ) {
return ERROR_INVALID_PARAMETER;
}
//
// Open the helper device.
//
RtlInitUnicodeString( &helperName, L"\\Device\\Afd\\Helper" );
InitializeObjectAttributes(
&objectAttributes, // ObjectAttributes
&helperName, // ObjectName
OBJ_CASE_INSENSITIVE, // Attributes
NULL, // RootDirectory
NULL // SecurityDescriptor
);
status = NtCreateFile(
HelperHandle, // FileHandle
GENERIC_READ | // DesiredAccess
GENERIC_WRITE |
SYNCHRONIZE,
&objectAttributes, // ObjectAttributes
&ioStatusBlock, // IoStatusBlock
NULL, // AllocationSize
0, // FileAttributes
FILE_SHARE_READ | // ShareAccess
FILE_SHARE_WRITE,
FILE_OPEN_IF, // CreateDisposition
FILE_SYNCHRONOUS_IO_NONALERT, // CreateOptions
NULL, // EaBuffer
0 // EaLength
);
if( NT_SUCCESS(status) ) {
return NO_ERROR;
}
return RtlNtStatusToDosError( status );
} // WahOpenApcHelper
DWORD
WINAPI
WahCloseApcHelper(
IN HANDLE HelperHandle
)
/*++
Routine Description:
This function closes the WinSock 2.0 APC helper device.
Arguments:
HelperHandle - The handle to close.
Return Value:
DWORD - NO_ERROR if successful, a Win32 error code if not.
--*/
{
NTSTATUS status;
//
// Validate parameters.
//
if( HelperHandle == NULL ) {
return ERROR_INVALID_PARAMETER;
}
//
// Close the handle.
//
status = NtClose( HelperHandle );
if( NT_SUCCESS(status) ) {
return NO_ERROR;
}
return RtlNtStatusToDosError( status );
} // WahCloseApcHelper
DWORD
WINAPI
WahOpenCurrentThread(
IN HANDLE HelperHandle,
OUT LPWSATHREADID ThreadId
)
/*++
Routine Description:
This function opens a handle to the current thread.
Arguments:
HelperHandle - An open handle to the APC helper device.
ThreadId - Points to a WSATHREADID structure that will receive
an open handle to the current thread and an (optional) OS-
dependent thread identifier.
Return Value:
DWORD - NO_ERROR if successful, a Win32 error code if not.
--*/
{
NTSTATUS status;
//
// Validate parameters.
//
if( ( HelperHandle == NULL ) ||
( ThreadId == NULL ) ) {
return ERROR_INVALID_PARAMETER;
}
//
// Duplicate the current thread pseudo handle.
//
status = NtDuplicateObject(
NtCurrentProcess(), // SourceProcessHandle
NtCurrentThread(), // SourceHandle
NtCurrentProcess(), // TargetProcessHandle
&ThreadId->ThreadHandle, // TargetHandle
0, // DesiredAccess
0, // HandleAttributes
DUPLICATE_SAME_ACCESS // Options
);
if( NT_SUCCESS(status) ) {
//
// The NT implementation of the APC helper does not really
// need the OS-dependent thread identifier, but we'll store
// the current thread ID in the structure just for completeness.
//
ThreadId->Reserved = (DWORD)NtCurrentTeb()->ClientId.UniqueThread;
return NO_ERROR;
}
return RtlNtStatusToDosError( status );
} // WahOpenCurrentThread
DWORD
WINAPI
WahCloseThread(
IN HANDLE HelperHandle,
IN LPWSATHREADID ThreadId
)
/*++
Routine Description:
This routine closes an open thread handle.
Arguments:
HelperHandle - An open handle to the APC helper device.
ThreadId - Points to a WSATHREADID structure initialized by a
previous call to WahOpenCurrentThread().
Return Value:
DWORD - NO_ERROR if successful, a Win32 error code if not.
--*/
{
NTSTATUS status;
UNREFERENCED_PARAMETER( HelperHandle );
//
// Validate parameters.
//
if( ( ThreadId == NULL ) ||
( ThreadId->ThreadHandle == NULL ) ) {
return ERROR_INVALID_PARAMETER;
}
//
// Close the handle.
//
status = NtClose( ThreadId->ThreadHandle );
if( NT_SUCCESS(status) ) {
//
// Clear the fields in case the client tries something stupid.
//
ThreadId->ThreadHandle = NULL;
ThreadId->Reserved = 0;
return NO_ERROR;
}
return RtlNtStatusToDosError( status );
} // WahCloseThread
DWORD
WINAPI
WahQueueUserApc(
IN HANDLE HelperHandle,
IN LPWSATHREADID ThreadId,
IN LPWSAUSERAPC ApcRoutine,
IN DWORD ApcContext OPTIONAL
)
/*++
Routine Description:
This routine queues a user-mode APC for the specified thread.
Arguments:
HelperHandle - An open handle to the APC helper device.
ThreadId - Points to a WSATHREADID structure initialized by a
previous call to WahOpenCurrentThread().
ApcRoutine - Points to the APC code to execute when the specified
thread enters an alertable wait.
ApcContext - An uninterpreted context value to pass to the APC routine.
Return Value:
DWORD - NO_ERROR if successful, a Win32 error code if not.
--*/
{
NTSTATUS status;
AFD_QUEUE_APC_INFO apcInfo;
IO_STATUS_BLOCK ioStatusBlock;
//
// Validate parameters.
//
if( ( HelperHandle == NULL ) ||
( ThreadId == NULL ) ||
( ThreadId->ThreadHandle == NULL ) ||
( ApcRoutine == NULL ) ) {
return ERROR_INVALID_PARAMETER;
}
//
// Ask the helper to queue the APC. We'll actually schedule
// WahpIntermediateApc as the "real" APC, which will unpack
// the parameters and call the routine specified by ApcRoutine.
//
apcInfo.Thread = ThreadId->ThreadHandle;
apcInfo.ApcRoutine = WahpIntermediateApc;
apcInfo.ApcContext = (PVOID)ApcContext;
apcInfo.SystemArgument1 = ApcRoutine;
apcInfo.SystemArgument2 = NULL;
status = NtDeviceIoControlFile(
HelperHandle, // FileHandle
NULL, // Event
NULL, // ApcRoutine
NULL, // ApcContext
&ioStatusBlock, // IoStatusBlock
IOCTL_AFD_QUEUE_APC, // IoControlCode
&apcInfo, // InputBuffer
sizeof(apcInfo), // InputBufferLength
NULL, // OutputBuffer
0 // OutputBufferLength
);
if( NT_SUCCESS(status) ) {
return NO_ERROR;
}
return RtlNtStatusToDosError( status );
} // WahQueueUserApc
//
// Private functions.
//
VOID
WINAPI
WahpIntermediateApc(
LPVOID Context,
LPVOID SystemArgument1,
LPVOID SystemArgument2
)
/*++
Routine Description:
This is the "real" APC as scheduled by the NT kernel. It packages
the parameters into the "portable" (with Win95) form, then calls the
user-specified APC function.
Arguments:
Context - The APC context. This is just the ApcContext as passed
into WahQueueUserApc.
SystemArgument1 - This points to the "portable" APC function (this
is the ApcRoutine as passed into WahQueueUserApc).
SystemArgument2 - Unused.
Return Value:
None.
--*/
{
UNREFERENCED_PARAMETER( SystemArgument2 );
//
// Just call through to the user's APC function.
//
((LPWSAUSERAPC)SystemArgument1)( (DWORD)Context );
} // WahpIntermediateApc