process.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         ReactOS CSR Sub System
 * FILE:            subsys/csr/csrsrv/process.c
 * PURPOSE:         CSR Server DLL Process Implementation
 * PROGRAMMERS:     Alex Ionescu ([e-mail])
 */

/* INCLUDES ******************************************************************/

#include "srv.h"

#define NDEBUG
#include <debug.h>

/* DATA **********************************************************************/

PCSR_PROCESS CsrRootProcess = NULL;
RTL_CRITICAL_SECTION CsrProcessLock;
ULONG CsrProcessSequenceCount = 5;
ULONG CsrTotalPerProcessDataLength;

/* PRIVATE FUNCTIONS *********************************************************/

/*++
 * @name CsrAllocateProcess
 * @implemented NT4
 *
 * The CsrAllocateProcess routine allocates a new CSR Process object.
 *
 * @return Pointer to the newly allocated CSR Process.
 *
 * @remarks None.
 *
 *--*/
PCSR_PROCESS
NTAPI
CsrAllocateProcess(VOID)
{
    PCSR_PROCESS CsrProcess;
    ULONG TotalSize;

    /* Calculate the amount of memory this should take */
    TotalSize = sizeof(CSR_PROCESS) +
                (CSR_SERVER_DLL_MAX * sizeof(PVOID)) +
                CsrTotalPerProcessDataLength;

    /* Allocate a Process */
    CsrProcess = RtlAllocateHeap(CsrHeap, HEAP_ZERO_MEMORY, TotalSize);
    if (!CsrProcess) return NULL;

    /* Handle the Sequence Number */
    CsrProcess->SequenceNumber = CsrProcessSequenceCount++;

    /* Increase the reference count */
    CsrProcess->ReferenceCount++;

    /* Initialize the Thread List */
    InitializeListHead(&CsrProcess->ThreadList);

    /* Return the Process */
    return CsrProcess;
}

/*++
 * @name CsrServerInitialization
 * @implemented NT4
 *
 * The CsrInitializeProcesses routine sets up support for CSR Processes
 * and CSR Threads.
 *
 * @param None.
 *
 * @return STATUS_SUCCESS in case of success, STATUS_UNSUCCESSFUL
 *         othwerwise.
 *
 * @remarks None.
 *
 *--*/
NTSTATUS
NTAPI
CsrInitializeProcesses(VOID)
{
    NTSTATUS Status;
    ULONG i;

    /* Initialize the Lock */
    Status = RtlInitializeCriticalSection(&CsrProcessLock);

    /* Set up the Root Process */
    CsrRootProcess = CsrAllocateProcess();
    if (!CsrRootProcess) return STATUS_NO_MEMORY;

    /* Set up the minimal information for it */
    InitializeListHead(&CsrRootProcess->ListLink);
    CsrRootProcess->ProcessHandle = (HANDLE)-1;
    CsrRootProcess->ClientId = NtCurrentTeb()->Cid;

    /* Initialize the Thread Hash List */
    for (i = 0; i < 256; i++) InitializeListHead(&CsrThreadHashTable[i]);

    /* Initialize the Wait Lock */
    Status = RtlInitializeCriticalSection(&CsrWaitListsLock);
    return Status;
}

/*++
 * @name CsrDeallocateProcess
 *
 * The CsrDeallocateProcess frees the memory associated with a CSR Process.
 *
 * @param CsrProcess
 *        Pointer to the CSR Process to be freed.
 *
 * @return None.
 *
 * @remarks Do not call this routine. It is reserved for the internal
 *          thread management routines when a CSR Process has been cleanly
 *          dereferenced and killed.
 *
 *--*/
VOID
NTAPI
CsrDeallocateProcess(IN PCSR_PROCESS CsrProcess)
{
    /* Free the process object from the heap */
    RtlFreeHeap(CsrHeap, 0, CsrProcess);
}

/*++
 * @name CsrInsertProcess
 *
 * The CsrInsertProcess routine inserts a CSR Process into the Process List
 * and notifies Server DLLs of the creation of a new CSR Process.
 *
 * @param Parent
 *        Optional pointer to the CSR Process creating this CSR Process.
 *
 * @param CurrentProcess
 *        Optional pointer to the current CSR Process.
 *
 * @param CsrProcess
 *        Pointer to the CSR Process which is to be inserted.
 *
 * @return None.
 *
 * @remarks None.
 *
 *--*/
VOID
NTAPI
CsrInsertProcess(IN PCSR_PROCESS Parent OPTIONAL,
                 IN PCSR_PROCESS CurrentProcess OPTIONAL,
                 IN PCSR_PROCESS CsrProcess)
{
    PCSR_SERVER_DLL ServerDll;
    ULONG i;

    /* Set the parent */
    CsrProcess->Parent = Parent;

    /* Insert it into the Root List */
    InsertTailList(&CsrRootProcess->ListLink, &CsrProcess->ListLink);

    /* Notify the Server DLLs */
    for (i = 0; i < CSR_SERVER_DLL_MAX; i++)
    {
        /* Get the current Server DLL */
        ServerDll = CsrLoadedServerDll[i];

        /* Make sure it's valid and that it has callback */
        if (ServerDll && ServerDll->NewProcessCallback)
        {
            (*ServerDll->NewProcessCallback)(CurrentProcess, CsrProcess);
        }
    }
}

/*++
 * @name CsrLockedDereferenceProcess
 *
 * The CsrLockedDereferenceProcess dereferences a CSR Process while the
 * Process Lock is already being held.
 *
 * @param CsrProcess
 *        Pointer to the CSR Process to be dereferenced.
 *
 * @return None.
 *
 * @remarks This routine will return with the Process Lock held.
 *
 *--*/
VOID
NTAPI
CsrLockedDereferenceProcess(PCSR_PROCESS CsrProcess)
{
    /* Decrease reference count */
    if (!(--CsrProcess->ReferenceCount))
    {
        /* Call the generic cleanup code */
        CsrAcquireProcessLock();
        CsrProcessRefcountZero(CsrProcess);
    }
}

/*++
 * @name CsrRemoveProcess
 *
 * The CsrRemoveProcess function undoes a CsrInsertProcess operation and
 * removes the CSR Process from the Process List and notifies Server DLLs
 * of this removal.
 *
 * @param CsrProcess
 *        Pointer to the CSR Process to remove.  
 *
 * @return None.
 *
 * @remarks None.
 *
 *--*/
VOID
NTAPI
CsrRemoveProcess(IN PCSR_PROCESS CsrProcess)
{
    PCSR_SERVER_DLL ServerDll;
    ULONG i;

    /* Remove us from the Process List */
    RemoveEntryList(&CsrProcess->ListLink);

    /* Release the lock */
    CsrReleaseProcessLock();

    /* Loop every Server DLL */
    for (i = 0; i < CSR_SERVER_DLL_MAX; i++)
    {
        /* Get the Server DLL */
        ServerDll = CsrLoadedServerDll[i];

        /* Check if it's valid and if it has a Disconnect Callback */
        if (ServerDll && ServerDll->DisconnectCallback)
        {
            /* Call it */
            (ServerDll->DisconnectCallback)(CsrProcess);
        }
    }
}

/*++
 * @name CsrProcessRefcountZero
 *
 * The CsrProcessRefcountZero routine is executed when a CSR Process has lost
 * all its active references. It removes and de-allocates the CSR Process.
 *
 * @param CsrProcess
 *        Pointer to the CSR Process that is to be deleted.
 *
 * @return None.
 *
 * @remarks Do not call this routine. It is reserved for the internal
 *          thread management routines when a CSR Process has lost all
 *          its references.
 *
 *          This routine is called with the Process Lock held.
 *
 *--*/
VOID
NTAPI
CsrProcessRefcountZero(IN PCSR_PROCESS CsrProcess)
{
    /* Remove the Process from the list */
    CsrRemoveProcess(CsrProcess);

    /* Check if there's a session */
    if (CsrProcess->NtSession)
    {
        /* Dereference the Session */
        CsrDereferenceNtSession(CsrProcess->NtSession, 0);
    }

    /* Close the Client Port if there is one */
    if (CsrProcess->ClientPort ) NtClose(CsrProcess->ClientPort);

    /* Close the process handle */
    NtClose(CsrProcess->ProcessHandle);

    /* Free the Proces Object */
    CsrDeallocateProcess(CsrProcess);
}

/*++
 * @name CsrSetToNormalPriority
 *
 * The CsrSetToNormalPriority routine sets the current NT Process'
 * priority to the normal priority for CSR Processes.
 *
 * @param None.
 *
 * @return None.
 *
 * @remarks The "Normal" Priority corresponds to the Normal Forground
 *          Priority (9) plus a boost of 4.
 *
 *--*/
VOID
NTAPI
CsrSetToNormalPriority(VOID)
{
    KPRIORITY BasePriority = (8 + 1) + 4;

    /* Set the Priority */
    NtSetInformationProcess(NtCurrentProcess(),
                            ProcessBasePriority,
                            &BasePriority,
                            sizeof(KPRIORITY));
}

/*++
 * @name CsrSetToShutdownPriority
 *
 * The CsrSetToShutdownPriority routine sets the current NT Process'
 * priority to the boosted priority for CSR Processes doing shutdown.
 * Additonally, it acquires the Shutdown Privilege required for shutdown.
 *
 * @param None.
 *
 * @return None.
 *
 * @remarks The "Shutdown" Priority corresponds to the Normal Forground
 *          Priority (9) plus a boost of 6.
 *
 *--*/
VOID
NTAPI
CsrSetToShutdownPriority(VOID)
{
    KPRIORITY SetBasePriority = (8 + 1) + 6;
    BOOLEAN Old;

    /* Get the shutdown privilege */
    if (NT_SUCCESS(RtlAdjustPrivilege(SE_SHUTDOWN_PRIVILEGE,
                                      TRUE,
                                      FALSE,
                                      &Old)))
    {
        /* Set the Priority */
        NtSetInformationProcess(NtCurrentProcess(),
                                ProcessBasePriority,
                                &SetBasePriority,
                                sizeof(KPRIORITY));
    }
}

/*++
 * @name FindProcessForShutdown
 *
 * The FindProcessForShutdown routine returns a CSR Process which is ready
 * to be shutdown, and sets the appropriate shutdown flags for it.
 *
 * @param CallerLuid
 *        Pointer to the LUID of the CSR Process calling this routine.
 *
 * @return Pointer to a CSR Process which is ready to be shutdown.
 *
 * @remarks None.
 *
 *--*/
PCSR_PROCESS
NTAPI
FindProcessForShutdown(PLUID CallerLuid)
{
    PLIST_ENTRY ListHead, NextEntry;
    LUID ProcessLuid;
    NTSTATUS Status;
    LUID SystemLuid = SYSTEM_LUID;
    PCSR_PROCESS CsrProcess;
    PCSR_THREAD CsrThread;
    BOOLEAN IsSystemLuid = FALSE, IsOurLuid = FALSE;
    PCSR_PROCESS ReturnCsrProcess = NULL;
    ULONG Level = 0;

    /* Set the List Pointers */
    ListHead = &CsrRootProcess->ListLink;
    NextEntry = ListHead->Flink;

    /* Start looping */
    while (NextEntry != ListHead)
    {
        /* Get the process */
        CsrProcess = CONTAINING_RECORD(NextEntry, CSR_PROCESS, ListLink);

        /* Move to the next entry */
        NextEntry = NextEntry->Flink;

        /* Skip this process if it's already been processed*/
        if (CsrProcess->Flags & CsrProcessSkipShutdown) continue;

        /* Get the LUID of this Process */
        Status = CsrGetProcessLuid(CsrProcess->ProcessHandle, &ProcessLuid);

        /* Check if we didn't get access to the LUID */
        if (Status == STATUS_ACCESS_DENIED)
        {
            /* Check if we have any threads */
            if (CsrProcess->ThreadCount)
            {
                /* Impersonate one of the threads and retry */
                CsrThread = CONTAINING_RECORD(CsrProcess->ThreadList.Flink,
                                              CSR_THREAD,
                                              Link);