windows-nt/Source/XPSP1/NT/base/fs/remotefs/dfs/inc/umrx.h

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/*++
Copyright (c) 2001 Microsoft Corporation
Module Name:
umrx.h
Abstract:
This header defines the UMRxEngine object and associated functions.
The UMRxEngine provides a set of services for dispatch function
writers so they can reflect requests to user-mode components.
Notes:
Code / Ideas have been adopted from Joe Linn's user-mode reflector
Author:
Rohan Phillips [Rohanp] 18-Jan-2001
--*/
#ifndef _UMRX_H_
#define _UMRX_H_
//
// defines and tags
//
#define UMRX_ENGINE_TAG (ULONG) 'xrmU'
#define UMRX_CONTEXT_TAG (ULONG) 'xtcU'
#define REASSIGN_MID 1
#define DONT_REASSIGN_MID 0
#define TICKS_PER_SECOND (10 * 1000 * 1000)
typedef USHORT NODE_TYPE_CODE;
typedef CSHORT NODE_BYTE_SIZE;
typedef struct _MRX_NORMAL_NODE_HEADER {
NODE_TYPE_CODE NodeTypeCode;
NODE_BYTE_SIZE NodeByteSize;
ULONG NodeReferenceCount;
} MRX_NORMAL_NODE_HEADER;
enum {
UMRX_ENGINE_STATE_STOPPED = 0,
UMRX_ENGINE_STATE_STARTING,
UMRX_ENGINE_STATE_STARTED,
UMRX_ENGINE_STATE_STOPPING
};
//
// Define the UMRxEngine object. There is one such object for
// every NET_ROOT. This object contains all the data str needed
// for routing kernel-mode requests to user-mode.
//
typedef struct _UMRX_ENGINE {
// MID to UMRxContext mapping table
struct {
PRX_MID_ATLAS MidAtlas;
FAST_MUTEX MidManagementMutex;
LIST_ENTRY WaitingForMidListhead;
};
struct {
KQUEUE Queue;
LARGE_INTEGER TimeOut;
LIST_ENTRY PoisonEntry;
ULONG NumberOfWorkerThreads;
ULONG NumberOfWorkItems;
ERESOURCE Lock;
ULONG State;
ULONG ThreadAborted;
} Q;
ULONG NextSerialNumber;
ULONG cUserModeReflectionsInProgress;
LIST_ENTRY ActiveLinkHead;
} UMRX_ENGINE, *PUMRX_ENGINE;
void
UMRxAbortPendingRequests(IN PUMRX_ENGINE pUMRxEngine);
//
// Forwards
//
struct _UMRX_CONTEXT;
typedef struct _UMRX_CONTEXT *PUMRX_CONTEXT;
//
// Signatures for function pointers
//
//
// Continue routine is called by InitiateRequest -
// This turns around and submits the request to the
// UMR engine with callbacks for FORMAT and COMPLETION.
//
typedef
NTSTATUS
(*PUMRX_CONTINUE_ROUTINE) (
PUMRX_CONTEXT pUMRxContext,
PRX_CONTEXT pRxContext
);
//
// Format routine - called before user-mode worker thread completes.
// Each dispatch routine will interpret the WORK_ITEM union based on opcode.
// eg: for Create, WorkItem is a CREATE_REQUEST.
//
typedef
NTSTATUS
(*PUMRX_USERMODE_FORMAT_ROUTINE) (
PUMRX_CONTEXT pUMRxContext,
PRX_CONTEXT pRxContext,
PUMRX_USERMODE_WORKITEM WorkItem,
ULONG WorkItemLength,
PULONG ReturnedLength
);
//
// Completion routine - called when user-mode response is received.
// Each dispatch routine will interpret the WORK_ITEM union based on opcode.
// eg: for Create, WorkItem is a CREATE_RESPONSE.
//
typedef
VOID
(*PUMRX_USERMODE_COMPLETION_ROUTINE) (
PUMRX_CONTEXT pUMRxContext,
PRX_CONTEXT pRxContext,
PUMRX_USERMODE_WORKITEM WorkItem,
ULONG WorkItemLength
);
//
// Type of operation reflected to user-mode
//
typedef enum _UMRX_CONTEXT_TYPE {
UMRX_CTXTYPE_IFSDFSLINK = 0,
UMRX_CTXTYPE_GETDFSREPLICAS,
UMRX_CTXTYPE_MAXIMUM
} UMRX_CONTEXT_TYPE;
//
// Define the UMRxContext. This context is sent as part of
// the REQUEST to user-mode. The user-mode handler will
// send the context back in a RESPONSE. The context will be
// used to do the rendezvous with blocked requests.
//
#define UMRX_NTC_CONTEXT ((USHORT)0xedd0)
typedef struct _UMRX_CONTEXT{
MRX_NORMAL_NODE_HEADER;
PUMRX_ENGINE pUMRxEngine; // owning engine object
PRX_CONTEXT RxContext;
PVOID SavedMinirdrContextPtr;
union {
IO_STATUS_BLOCK;
IO_STATUS_BLOCK IoStatusBlock;
};
UMRX_CONTEXT_TYPE CTXType;
PUMRX_CONTINUE_ROUTINE Continuation;
struct {
LIST_ENTRY WorkQueueLinks;
PUMRX_USERMODE_FORMAT_ROUTINE FormatRoutine;
PUMRX_USERMODE_COMPLETION_ROUTINE CompletionRoutine;
KEVENT WaitForMidEvent;
ULONG CallUpSerialNumber;
USHORT CallUpMid;
} UserMode;
LIST_ENTRY ActiveLink;
} UMRX_CONTEXT, *PUMRX_CONTEXT;
#define UMRxReferenceContext(pUMRxContext) {\
ULONG result = InterlockedIncrement(&(pUMRxContext)->NodeReferenceCount); \
RxDbgTrace(0, (DEBUG_TRACE_UMRX), \
("ReferenceContext result=%08lx\n", result )); \
}
typedef struct _UMRX_WORKITEM_HEADER_PRIVATE {
PUMRX_CONTEXT pUMRxContext;
ULONG SerialNumber;
USHORT Mid;
} UMRX_WORKITEM_HEADER_PRIVATE, *PUMRX_WORKITEM_HEADER_PRIVATE;
//
// Create a UMRX_ENGINE object
//
PUMRX_ENGINE
CreateUMRxEngine();
//
// Close a UMRX_ENGINE object -
// Owner of object ensures that all usage of this object
// is within the Create/Finalize span.
//
VOID
FinalizeUMRxEngine(
IN PUMRX_ENGINE pUMRxEngine
);
//
// Complete queued requests and optional cleanup when the store has exited
//
NTSTATUS
UMRxEngineCompleteQueuedRequests(
IN PUMRX_ENGINE pUMRxEngine,
IN NTSTATUS CompletionStatus,
IN BOOLEAN fCleanup
);
//
// Used to allow an engine to be used again after it's been shutdown.
//
//
NTSTATUS
UMRxEngineRestart(
IN PUMRX_ENGINE pUMRxEngine
);
//
// Initiate a request to the UMR engine -
// This creates a UMRxContext that is used for response rendezvous.
// All IFS dispatch routines will start a user-mode reflection by
// calling this routine. Steps in routine:
//
// 1. Allocate a UMRxContext and set RxContext
// (NOTE: need to have ASSERTs that validate this linkage)
// 2. Set Continue routine ptr and call Continue routine
// 3. If Continue routine is done ie not PENDING, Finalize UMRxContext
//
NTSTATUS
UMRxEngineInitiateRequest (
IN PUMRX_ENGINE pUMRxEngine,
IN PRX_CONTEXT RxContext,
IN UMRX_CONTEXT_TYPE RequestType,
IN PUMRX_CONTINUE_ROUTINE Continuation
);
//
// Create/Finalize UMRX_CONTEXTs
// These are pool allocs/frees
//
PUMRX_CONTEXT
UMRxCreateAndReferenceContext (
IN PRX_CONTEXT RxContext,
IN UMRX_CONTEXT_TYPE RequestType
);
BOOLEAN
UMRxDereferenceAndFinalizeContext (
IN OUT PUMRX_CONTEXT pUMRxContext
);
//
// Submit a request to the UMR engine -
// This adds the request to the engine KQUEUE for processing by
// a user-mode thread. Steps:
//
// 1. set the FORMAT and COMPLETION callbacks in the UMRxContext
// 2. initialize the RxContext sync event
// 3. insert the UMRxContext into the engine KQUEUE
// 4. block on RxContext sync event (for SYNC operations)
// 5. after unblock (ie umode response is back), call Resume routine
//
NTSTATUS
UMRxEngineSubmitRequest(
IN PUMRX_CONTEXT pUMRxContext,
IN PRX_CONTEXT pRxContext,
IN UMRX_CONTEXT_TYPE RequestType,
IN PUMRX_USERMODE_FORMAT_ROUTINE FormatRoutine,
IN PUMRX_USERMODE_COMPLETION_ROUTINE CompletionRoutine
);
//
// Resume is called after I/O thread is unblocked by umode RESPONSE.
// This routine calls any Finish callbacks and then Finalizes the
// UMRxContext.
//
NTSTATUS
UMRxResumeEngineContext(
IN OUT PRX_CONTEXT RxContext
);
//
// The following functions run in the context of user-mode
// worker threads that issue WORK IOCTLs. The IOCTL calls the
// following functions in order:
// 1. UMRxCompleteUserModeRequest() - process a response if needed
// 2. UMRxEngineProcessRequest() - process a request if one is
// available on the UMRxEngine KQUEUE. Since these IOCTLs are
// made on a NET_ROOT, the corresponding UMRxEngine is readily
// available in the NET_ROOT extension.
//
//
// Every IOCTL pended is potentially a Response. If so, process it.
// The first IOCTL pended is usually a NULL Response or 'listen'.
// Steps:
// 1. Get MID from response buffer. Map MID to UMRxContext.
// 2. Call UMRxContext COMPLETION routine.
// 3. Unblock the I/O thread waiting in UMRxEngineSubmitRequest()
//
NTSTATUS
UMRxCompleteUserModeRequest(
IN PUMRX_ENGINE pUMRxEngine,
IN OUT PUMRX_USERMODE_WORKITEM WorkItem,
IN ULONG WorkItemLength,
IN BOOLEAN fReleaseUmrRef,
OUT PIO_STATUS_BLOCK IoStatus,
OUT BOOLEAN * pfReturnImmediately
);
//
// NOTE: if no requests are available, the user-mode thread will
// block till a request is available (It is trivial to make this
// a more async model).
//
// If a request is available, get the corresponding UMRxContext and
// call ProcessRequest.
// Steps:
// 1. Call KeRemoveQueue() to remove a request from the UMRxEngine KQUEUE.
// 2. Get a MID for this UMRxContext and fill it in the WORK_ITEM header.
// 3. Call the UMRxContext FORMAT routine - this fills in the Request params.
// 4. return STATUS_SUCCESS - this causes the IOCTL to complete which
// triggers the user-mode completion and processing of the REQUEST.
//
NTSTATUS
UMRxEngineProcessRequest(
IN PUMRX_ENGINE pUMRxEngine,
OUT PUMRX_USERMODE_WORKITEM WorkItem,
IN ULONG WorkItemLength,
OUT PULONG FormattedWorkItemLength
);
//
// This is called in response to a WORK_CLEANUP IOCTL.
// This routine will insert a dummy item in the engine KQUEUE.
// Each such dummy item inserted will release one thread.
//
NTSTATUS
UMRxEngineReleaseThreads(
IN PUMRX_ENGINE pUMRxEngine
);
//
// Cancel I/O infrastructure
//
typedef
NTSTATUS
(NTAPI *PUMRX_CANCEL_ROUTINE) (
PRX_CONTEXT pRxContext);
// The RX_CONTEXT instance has four fields ( ULONG's ) provided by the wrapper
// which can be used by the mini rdr to store its context. This is used by
// the reflector to identify the parameters for request cancellation
typedef struct _UMRX_RX_CONTEXT {
PUMRX_CANCEL_ROUTINE pCancelRoutine;
PVOID pCancelContext;
union {
struct {
PUMRX_CONTEXT pUMRxContext;
ULONG RxSyncTimeout;
};
IO_STATUS_BLOCK SyncCallDownIoStatus;
};
} UMRX_RX_CONTEXT, *PUMRX_RX_CONTEXT;
#define UMRxGetMinirdrContext(pRxContext) \
((PUMRX_RX_CONTEXT)(&(pRxContext)->UMRScratchSpace[0]))
#endif // _UMRX_H_