windows-xp/Source/XPSP1/NT/base/eventlog/server/elfapi.c

/*++

Copyright (c) 1991  Microsoft Corporation

Module Name:

    ELFAPI.C

Abstract:

    This module contains the server end of the Elf APIs.


Author:

    Rajen Shah  (rajens)    29-Jul-1991


Revision History:

    14-May-01           a-jyotig
        Removed impersonation from ElfrClearELFW as it is no longer required to
		identify the client that clears a log.

	02-Mar-01           drbeck
        Modified ElfrClearELFW to impersonate client so that a SACL placed on the
        system event log will correctly identify the client that clears a log.
        
                
    10-Sep-1998         jschwart
        Added ElfrGetLogInformation (GetEventlogInformation) API

    30-Jan-1995         MarkBl
        Backup operators are allowed to open the security log, but only
        to perform backup operations. All other operations are prohibited.

    13-Oct-1993         Danl
        ElfrOpenELA:  Fixed Memory Leak bug where it was not calling
        RtlFreeUnicodeString for pRegModuleNameU and PModuleNameU.

    29-Jul-1991         RajenS
        Created

--*/
/****
@doc    EXTERNAL INTERFACES EVTLOG
****/


#include <eventp.h>
#include <elfcfg.h>
#include <stdio.h>  // swprintf
#include <stdlib.h>
#include <memory.h>
#include <clussprt.h>

//
// Maximum number of ChangeNotify requests per context handle
//
#define MAX_NOTIFY_REQUESTS     5

#if defined(_WIN64)
#define ALIGN_UP_64(x,t) (((x) + (t) - 1) & ~((t)-1))
#else
#define ALIGN_UP_64(x,t) (x)
#endif


//
//  PROTOTYPES
//
NTSTATUS
ElfpOpenELW (
    IN  EVENTLOG_HANDLE_W   UNCServerName,
    IN  PRPC_UNICODE_STRING ModuleName,
    IN  PRPC_UNICODE_STRING RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle,
    IN  ULONG               DesiredAccess
    );

NTSTATUS
ElfpOpenELA (
    IN  EVENTLOG_HANDLE_A   UNCServerName,
    IN  PRPC_STRING         ModuleName,
    IN  PRPC_STRING         RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle,
    IN  ULONG               DesiredAccess
    );

VOID
FreePUStringArray (
    IN  PUNICODE_STRING  * pUStringArray,
    IN  USHORT             NumStrings
    );

NTSTATUS
VerifyElfHandle(
    IN IELF_HANDLE LogHandle
    );

NTSTATUS
VerifyUnicodeString(
    IN PUNICODE_STRING pUString
    );

NTSTATUS
VerifyAnsiString(
    IN PANSI_STRING pAString
    );



//
// These APIs only have one interface, since they don't take or return strings
//

NTSTATUS
ElfrNumberOfRecords(
    IN  IELF_HANDLE     LogHandle,
    OUT PULONG          NumberOfRecords
    )
/*++

Routine Description:

  This is the RPC server entry point for the ElfrCurrentRecord API.

Arguments:

    LogHandle       - The context-handle for this module's call.

    NumberOfRecords - Where to return the total number of records in the
                      log file.

Return Value:

    Returns an NTSTATUS code.


--*/
{
    PLOGMODULE Module;
    NTSTATUS   Status;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrNumberOfRecords: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Insure the caller has read access.
    //

    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_READ))
    {
        ELF_LOG0(ERROR,
                 "ElfrNumberOfRecords: LogHandle doesn't have read access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //

    if (NumberOfRecords == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrNumberOfRecords: NumberOfRecords is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //

    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrNumberOfRecords: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // If the OldestRecordNumber is 0, that means we have an empty
    // file, else we calculate the difference between the oldest
    // and next record numbers
    //

    Module = FindModuleStrucFromAtom(LogHandle->Atom);

    if (Module != NULL)
    {
        *NumberOfRecords = Module->LogFile->OldestRecordNumber == 0 ? 0 :
        Module->LogFile->CurrentRecordNumber -
            Module->LogFile->OldestRecordNumber;
    }
    else
    {
        ELF_LOG0(ERROR,
                 "ElfrNumberOfRecords: No module struc associated with atom\n");

        Status = STATUS_INVALID_HANDLE;
    }

    return Status;
}


NTSTATUS
ElfrOldestRecord(
    IN  IELF_HANDLE         LogHandle,
    OUT PULONG          OldestRecordNumber
    )
{
    PLOGMODULE Module;
    NTSTATUS   Status;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrOldestRecord: VerifyElfHandle failed %#x\n",
                  Status);

        return Status;
    }

    //
    // Insure the caller has read access.
    //

    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_READ))
    {
        ELF_LOG0(ERROR,
                 "ElfrOldestRecord: LogHandle doesn't have read access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //
    if (OldestRecordNumber == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrOldestRecord: OldestRecordNumber is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //
    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrOldestRecord: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    Module = FindModuleStrucFromAtom (LogHandle->Atom);

    if (Module != NULL)
    {
        *OldestRecordNumber = Module->LogFile->OldestRecordNumber;
    }
    else
    {
        ELF_LOG0(ERROR,
                 "ElfrOldestRecord: No module struc associated with atom\n");

        Status = STATUS_INVALID_HANDLE;
    }

    return Status;
}


NTSTATUS
ElfrChangeNotify(
    IN  IELF_HANDLE         LogHandle,
    IN  RPC_CLIENT_ID       ClientId,
    IN  ULONG               Event
    )
{
    NTSTATUS Status;
    NTSTATUS RpcStatus;
    OBJECT_ATTRIBUTES ObjectAttributes;
    HANDLE ProcessHandle = NULL;
    HANDLE EventHandle;
    PLOGMODULE Module;
    PNOTIFIEE Notifiee;
    CLIENT_ID tempCli;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrChangeNotify: VerifyElfHandle failed %#x\n",
                  Status);

        return Status;
    }

    //
    // Ensure the caller has read access.
    //
    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_READ))
    {
        ELF_LOG0(ERROR,
                 "ElfrChangeNotify: LogHandle doesn't have read access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // First make sure that this is a local call and that it is not a
    // handle that was created for a backup log file
    //

    if (LogHandle->Flags & ELF_LOG_HANDLE_REMOTE_HANDLE ||
        LogHandle->Flags & ELF_LOG_HANDLE_BACKUP_LOG)
    {
        ELF_LOG1(ERROR,
                 "ElfrChangeNotify: Handle is for a %ws log\n",
                 LogHandle->Flags & ELF_LOG_HANDLE_REMOTE_HANDLE ? L"remote" :
                                                                   L"backup");

        return STATUS_INVALID_HANDLE;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //

    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrChangeNotify: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Make sure the client has the right to open this process
    //

    RpcStatus = RpcImpersonateClient(NULL);

    if (RpcStatus != RPC_S_OK)
    {
        ELF_LOG1(ERROR,
                 "ElfrChangeNotify: RpcImpersonateClient failed %#x\n",
                 RpcStatus);

        return RpcStatus;
    }

    //
    // First get a handle to the process using the passed in ClientId. Note
    // that the ClientId is supplied by the client so a rogue client may
    // supply any client ID. However, because we impersonate when opening
    // the process we don't get any additional access the client doesn't have.
    //
    InitializeObjectAttributes(&ObjectAttributes,
                               NULL,                   // UNICODE string
                               0,                      // Attributes
                               NULL,                   // Root directory
                               NULL);                  // Security descriptor

#ifdef _WIN64

    tempCli.UniqueProcess = (HANDLE)ULongToPtr(ClientId.UniqueProcess);
    tempCli.UniqueThread = (HANDLE)ULongToPtr(ClientId.UniqueThread);

    Status = NtOpenProcess(&ProcessHandle,
                           PROCESS_DUP_HANDLE,
                           &ObjectAttributes,
                           &tempCli);

#else
    Status = NtOpenProcess(&ProcessHandle,
                           PROCESS_DUP_HANDLE,
                           &ObjectAttributes,
                           (PCLIENT_ID) &ClientId);
#endif

    RpcStatus = RpcRevertToSelf();

    if (RpcStatus != RPC_S_OK)
    {
        ELF_LOG1(ERROR,
                 "ElfrChangeNotify: RpcRevertToSelf failed %#x\n",
                 RpcStatus);
    }

    if (NT_SUCCESS(Status))
    {
        //
        // Now dupe the handle they passed in for the event
        //
        Status = NtDuplicateObject(ProcessHandle,
                                   LongToHandle(Event),
                                   NtCurrentProcess(),
                                   &EventHandle,
                                   0,
                                   0,
                                   DUPLICATE_SAME_ACCESS);

         if (NT_SUCCESS(Status))
         {
             //
             // Create a new NOTIFIEE control block to link in
             //
             Notifiee = ElfpAllocateBuffer(sizeof(NOTIFIEE));

             if (Notifiee)
             {
                 //
                 // Fill in the fields
                 //
                 Notifiee->Handle = LogHandle;
                 Notifiee->Event = EventHandle;

                 //
                 // Find the LOGFILE associated with this handle
                 //
                 Module = FindModuleStrucFromAtom(LogHandle->Atom);

                 if (Module != NULL)
                 {
                     //
                     // Get exclusive access to the log file. This will ensure
                     // no one else is accessing the file.
                     //
                     RtlAcquireResourceExclusive(&Module->LogFile->Resource,
                                                 TRUE);   // Wait until available

                     //
                     // Enforce the limit of ChangeNotify requests per context handle
                     //
                     if (LogHandle->dwNotifyRequests == MAX_NOTIFY_REQUESTS)
                     {
                         ELF_LOG1(ERROR,
                                  "ElfrChangeNotify: Already %d requests for this handle\n",
                                  MAX_NOTIFY_REQUESTS);

                         NtClose(EventHandle);
                         ElfpFreeBuffer(Notifiee);
                         Status = STATUS_INSUFFICIENT_RESOURCES;
                     }
                     else
                     {
                         //
                         // Insert the new notifiee into the list and increment this
                         // context handle's ChangeNotify request count
                         //
                         InsertHeadList(&Module->LogFile->Notifiees,
                                        &Notifiee->Next);

                         LogHandle->dwNotifyRequests++;
                     }

                     //
                     // Free the resource
                     //
                     RtlReleaseResource ( &Module->LogFile->Resource );
                 }
                 else
                 {
                     ELF_LOG0(ERROR,
                              "ElfrChangeNotify: No module struc associated with atom\n");

                     NtClose(EventHandle);
                     ElfpFreeBuffer(Notifiee);
                     Status = STATUS_INVALID_HANDLE;
                 }
             }
             else
             {
                 ELF_LOG0(ERROR,
                          "ElfrChangeNotify: Unable to allocate NOTIFIEE block\n");

                 Status = STATUS_NO_MEMORY;

                 //
                 // Free the duplicated handle
                 //
                 CloseHandle(EventHandle);
             }
         }
         else
         {
             ELF_LOG1(ERROR,
                      "ElfrChangeNotify: NtDuplicateObject failed %#x\n",
                      Status);
         }
    }
    else
    {
        ELF_LOG1(ERROR,
                 "ElfrChangeNotify: NtOpenProcess failed %#x\n",
                 Status);

        if (Status == STATUS_INVALID_CID)
        {
            Status = STATUS_INVALID_HANDLE;
        }
    }

    if (ProcessHandle)
    {
        NtClose(ProcessHandle);
    }

    return Status;
}


NTSTATUS
ElfrGetLogInformation(
    IN     IELF_HANDLE    LogHandle,
    IN     ULONG          InfoLevel,
    OUT    PBYTE          lpBuffer,
    IN     ULONG          cbBufSize,
    OUT    PULONG         pcbBytesNeeded
    )
/*++

Routine Description:

  This is the RPC server entry point for the ElfrGetLogInformation API.

Arguments:

    LogHandle      - The context-handle for this module's call.
    InfoLevel      - Infolevel that specifies which information the user is requesting
    lpBuffer       - Buffer into which to place the information
    cbBufSize      - Size of lpBuffer, in bytes
    pcbBytesNeeded - Required size of the buffer

Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS   ntStatus;
    PLOGMODULE pLogModule;

    //
    // Check the handle before proceeding.
    //
    ntStatus = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(ntStatus))
    {
        ELF_LOG1(ERROR,
                 "ElfrGetLogInformation: VerifyElfHandle failed %#x\n",
                 ntStatus);

        return ntStatus;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //

    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrGetLogInformation: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Take the appropriate actions based on the Infolevel
    //
    switch (InfoLevel)
    {
        case EVENTLOG_FULL_INFO:

            *pcbBytesNeeded = sizeof(EVENTLOG_FULL_INFORMATION);

            if (cbBufSize < *pcbBytesNeeded)
            {
                ELF_LOG2(ERROR,
                         "ElfrGetLogInformation: buffer size = %d, required size = %d\n",
                         cbBufSize,
                         *pcbBytesNeeded);

                ntStatus = STATUS_BUFFER_TOO_SMALL;
                break;
            }

            //
            // Get the module associated with this log handle
            //
            pLogModule = FindModuleStrucFromAtom(LogHandle->Atom);

            if (pLogModule != NULL)
            {
                //
                // The caller has the permission for this operation.  Note
                // that an access check is done when opening the log, so
                // there's no need to repeat it here.
                //
                ((LPEVENTLOG_FULL_INFORMATION)lpBuffer)->dwFull =

                    (pLogModule->LogFile->Flags & ELF_LOGFILE_LOGFULL_WRITTEN ?
                         TRUE :
                         FALSE);

                ELF_LOG2(TRACE,
                         "ElfrGetLogInformation: %ws log is %ws\n",
                         pLogModule->LogFile->LogModuleName->Buffer,
                         pLogModule->LogFile->Flags & ELF_LOGFILE_LOGFULL_WRITTEN ?
                             L"full" :
                             L"not full");
            }
            else
            {
                ELF_LOG0(ERROR,
                         "ElfrGetLogInformation: No module struc associated with atom\n");

                ntStatus = STATUS_INVALID_HANDLE;
            }

            break;

        default:

            ELF_LOG1(ERROR,
                     "ElfrGetLogInformation: Invalid InfoLevel %d\n",
                     InfoLevel);

            ntStatus = STATUS_INVALID_LEVEL;
            break;
    }

    return ntStatus;
}


//
// UNICODE APIs
//



NTSTATUS
ElfrClearELFW (
    IN  IELF_HANDLE         LogHandle,
    IN  PRPC_UNICODE_STRING BackupFileName
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrClearELFW API.

  CleanExit lable was written to add some cleanup code. The cleanup code was 
  removed later as it was not required but the lable is retained in order to 
  add any cleanup code if required in future 

Arguments:

    LogHandle       - The context-handle for this module's call.  This must
                      not have been returned from OpenBackupEventlog, or
                      this call will fail with invalid handle.

    BackupFileName  - Name of the file to back up the current log file.
                      NULL implies not to back up the file.


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS            Status;
    PLOGMODULE          Module;
    ELF_REQUEST_RECORD  Request;
    CLEAR_PKT           ClearPkt;
    DWORD               status = NO_ERROR;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrClearELFW: VerifyElfHandle failed %#x\n",
                 Status);

        goto CleanExit;
    }

    //
    // Ensure the caller has clear access.
    //
    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_CLEAR))
    {
        ELF_LOG0(ERROR,
                 "ElfrClearELFW: LogHandle doesn't have clear access\n");

        Status = STATUS_ACCESS_DENIED;
        goto CleanExit;
    }

    //
    // Verify additional arguments.
    //
    if (BackupFileName != NULL)
    {
        Status = VerifyUnicodeString(BackupFileName);

        if (!NT_SUCCESS(Status))
        {
            ELF_LOG0(ERROR,
                     "ElfrClearELFW: BackupFileName is an invalid Unicode string\n");

            goto CleanExit;
        }
    }

    //
    // Can't clear a backup log
    //

    if (LogHandle->Flags & ELF_LOG_HANDLE_BACKUP_LOG)
    {
        ELF_LOG0(ERROR,
                 "ElfrClearELFW: Handle is for a backup log\n");

        Status = STATUS_INVALID_HANDLE;
        goto CleanExit;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //
    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrClearELFW: Handle is a backup handle\n");

        Status = STATUS_ACCESS_DENIED;
        goto CleanExit;
    }

    //
    // Find the matching module structure
    //

    Module = FindModuleStrucFromAtom (LogHandle->Atom);

    Request.Pkt.ClearPkt = &ClearPkt;
    Request.Flags = 0;

    if (Module != NULL)
    {
        //
        // Verify that the caller has clear access to this logfile
        //

        if (!RtlAreAllAccessesGranted(LogHandle->GrantedAccess,
                                      ELF_LOGFILE_CLEAR))
        {
            ELF_LOG1(ERROR,
                     "ElfrClearELFW: Caller does not have clear access to %ws log\n",
                     Module->LogFile->LogModuleName->Buffer);

            Status = STATUS_ACCESS_DENIED;
        }

        if (NT_SUCCESS(Status))
        {
            //
            // Fill in the request packet
            //

            Request.Module = Module;
            Request.LogFile = Module->LogFile;
            Request.Command = ELF_COMMAND_CLEAR;
            Request.Status = STATUS_SUCCESS;
            Request.Pkt.ClearPkt->BackupFileName =
                                (PUNICODE_STRING)BackupFileName;

            //
            // Call the worker routine to do the operation.
            //

            ElfPerformRequest(&Request);

            //
            // Extract status of operation from the request packet
            //

            Status = Request.Status;

            //
            // If this was the Security Logfile, and the clear was
            // successful, then generate an audit.
            //
            if (NT_SUCCESS(Status) &&
                (_wcsicmp(ELF_SECURITY_MODULE_NAME,
                          Module->LogFile->LogModuleName->Buffer) == 0))
            {
                //
                // We just cleared the security log.  Now we want to add
                // a new event to that log to indicate who did it.
                //
                ElfpGenerateLogClearedEvent(LogHandle);
            }
        }
    }
    else
    {
        ELF_LOG0(ERROR,
                 "ElfrClearELFW: No module struc associated with atom\n");

        Status = STATUS_INVALID_HANDLE;
    }

CleanExit:

    return Status;
}


NTSTATUS
ElfrBackupELFW (
    IN  IELF_HANDLE         LogHandle,
    IN  PRPC_UNICODE_STRING BackupFileName
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrBackupELFW API.

Arguments:

    LogHandle       - The context-handle for this module's call.

    BackupFileName  - Name of the file to back up the current log file.


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS            Status;
    PLOGMODULE          Module;
    ELF_REQUEST_RECORD  Request;
    BACKUP_PKT          BackupPkt;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrBackupELFW: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Ensure the caller has read access.
    //

    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_READ))
    {
        ELF_LOG0(ERROR,
                 "ElfrBackupELFW: LogHandle doesn't have read access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Make sure the client has SE_BACKUP_PRIVILEGE enabled.  Note
    // that we attempted to enable this on the client side
    //
    if (ElfpTestClientPrivilege(SE_BACKUP_PRIVILEGE, NULL) != STATUS_SUCCESS)
    {
        ELF_LOG0(ERROR,
                 "ElfrBackupELFW: Client does not have SE_BACKUP_PRIVILEGE\n");

        return(STATUS_PRIVILEGE_NOT_HELD);
    }

    //
    // Verify additional arguments.
    //
    Status = VerifyUnicodeString(BackupFileName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG0(ERROR,
                 "ElfrBackupELFW: BackupFileName is not a valid Unicode string\n");

        return Status;
    }

    //
    // A filename must be specified.
    //

    if (BackupFileName->Length == 0) {
        return(STATUS_INVALID_PARAMETER);
    }

    Request.Pkt.BackupPkt = &BackupPkt;
    Request.Flags = 0;

    //
    // Find the matching module structure
    //
    Module = FindModuleStrucFromAtom(LogHandle->Atom);

    if (Module != NULL)
    {
        //
        // Fill in the request packet

        Request.Module  = Module;
        Request.LogFile = Module->LogFile;
        Request.Command = ELF_COMMAND_BACKUP;
        Request.Status  = STATUS_SUCCESS;
        Request.Pkt.BackupPkt->BackupFileName =
                            (PUNICODE_STRING)BackupFileName;

        //
        // Call the worker routine to do the operation.
        //
        ElfPerformRequest (&Request);

        //
        // Extract status of operation from the request packet
        //
        Status = Request.Status;
    }
    else
    {
        ELF_LOG0(ERROR,
                 "ElfrBackupELFW: No module struc associated with atom\n");

        Status = STATUS_INVALID_HANDLE;
    }

    return Status;
}


NTSTATUS
ElfrCloseEL (
    IN OUT  PIELF_HANDLE    LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrCloseEL API.

Arguments:


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS Status;

    //
    // Check the handle before proceeding.
    //
    if (LogHandle == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrCloseEL: LogHandle is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    Status = VerifyElfHandle(*LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrCloseEL: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Call the rundown routine to do all the work
    //
    IELF_HANDLE_rundown(*LogHandle);

    *LogHandle = NULL; // so RPC knows it's closed

    return STATUS_SUCCESS;
}


NTSTATUS
ElfrDeregisterEventSource(
    IN OUT  PIELF_HANDLE    LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrDeregisterEventSource API.

Arguments:


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS Status;

    if (LogHandle == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrDeregisterEventSource: LogHandle is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // Check the handle before proceeding.
    //
    Status = VerifyElfHandle(*LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrDeregisterEventSource: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //
    if ((*LogHandle)->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrDeregisterEventSource: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Call the rundown routine to do all the work
    //
    IELF_HANDLE_rundown(*LogHandle);

    *LogHandle = NULL; // so RPC knows it's closed

    return STATUS_SUCCESS;
}



NTSTATUS
ElfrOpenBELW (
    IN  EVENTLOG_HANDLE_W   UNCServerName,
    IN  PRPC_UNICODE_STRING BackupFileName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrOpenBELW API.  It creates
  a module structure $BACKUPnnn where nnn is a unique number for every backup
  log that is opened.  It then calls ElfpOpenELW to actually open the file.


Arguments:

    UNCServerName   - Not used.

    BackupFileName  - Name of the backup log file.

    MajorVersion/MinorVersion - The version of the client.


    LogHandle       - Pointer to the place where the pointer to the
                              context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".


--*/
{

    NTSTATUS        Status;
    UNICODE_STRING  BackupStringW;
    LPWSTR          BackupModuleName;
    PLOGMODULE      pModule;
    DWORD           dwModuleNumber;

//
// Size of buffer (in bytes) required for a UNICODE string of $BACKUPnnn
//

#define SIZEOF_BACKUP_MODULE_NAME 64

    UNREFERENCED_PARAMETER(UNCServerName);

    //
    // Check arguments.
    //

    Status = VerifyUnicodeString(BackupFileName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG0(ERROR,
                 "ElfrOpenBELW: BackupFileName is not a Unicode string\n");

        return Status;
    }

    //
    // A filename must be specified.
    //
    if (BackupFileName->Length == 0)
    {
        ELF_LOG0(ERROR,
                 "ElfrOpenBELW: Length of BackupFileName is 0\n");

        return STATUS_INVALID_PARAMETER;
    }

    if (LogHandle == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrOpenBELW: LogHandle is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // Create a unique module name by incrementing a global value
    //
    BackupModuleName = ElfpAllocateBuffer(SIZEOF_BACKUP_MODULE_NAME);

    if (BackupModuleName == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrOpenBELW: Unable to allocate memory for BackupModuleName\n");

        return STATUS_NO_MEMORY;
    }

    //
    // Serialize read, increment of the global backup module number.
    // Note: double-timing the log file list critical section so as to not
    // require another critical section specifically dedicated to this
    // operation.
    //
    RtlEnterCriticalSection (&LogFileCritSec);

    dwModuleNumber = BackupModuleNumber++;

    RtlLeaveCriticalSection (&LogFileCritSec);

    swprintf(BackupModuleName, L"$BACKUP%06d", dwModuleNumber);
    RtlInitUnicodeString(&BackupStringW, BackupModuleName);

    ELF_LOG2(TRACE,
             "ElfrOpenBELW: Backing up module %ws to file %ws\n",
             BackupModuleName,
             BackupFileName->Buffer);

    //
    // Call SetupDataStruct to build the module and log data structures
    // and actually open the file.
    //
    // NOTE:  If this call is successful, the Unicode String Buffer for
    //  BackupStringW (otherwise known as BackupModuleName) will be attached
    //  to the LogModule structure, and should not be free'd.
    //
    Status = SetUpDataStruct(
                    BackupFileName,  // Filename
                    0,               // Max size, it will use actual
                    0,               // retention period, not used for bkup
                    ELF_GUEST_ACCESS_UNRESTRICTED,  // restrict guest
                                     // access flag, inapplicable for bkup
                    &BackupStringW,  // Module name
                    NULL,            // Handle to registry, not used
                    ElfBackupLog,    // Log type
                    LOGPOPUP_NEVER_SHOW,
                    ELF_DEFAULT_AUTOBACKUP);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG3(ERROR,
                 "ElfrOpenBELW: SetUpDataStruct for file %ws (module %ws) failed %#x\n",
                 BackupFileName->Buffer,
                 BackupModuleName,
                 Status);

        ElfpFreeBuffer(BackupModuleName);
        return Status;
    }

    //
    // Call ElfOpenELW to actually open the log file and get a handle.
    //
    Status = ElfpOpenELW(NULL,
                         (PRPC_UNICODE_STRING) &BackupStringW,
                         NULL,
                         MajorVersion,
                         MinorVersion,
                         LogHandle,
                         ELF_LOGFILE_READ);

    if (NT_SUCCESS(Status))
    {
        //
        // Mark this as a handle for a backup log, so we can clean up
        // differently when it's closed, as well as disallow clear, backup
        // and write operations.
        //

        (*LogHandle)->Flags |= ELF_LOG_HANDLE_BACKUP_LOG;
    }
    else
    {
        ELF_LOG3(ERROR,
                 "ElfrOpenBELW: ElfpOpenELW for file %ws (module %ws) failed %#x\n",
                 BackupFileName->Buffer,
                 BackupModuleName,
                 Status);

        //
        // If we couldn't open the log file, then we need to tear down
        // the DataStruct we set up with SetUpDataStruct.
        //
        pModule = GetModuleStruc(&BackupStringW);

        //
        // We'd better be unlinking the same module we just created
        //
        ASSERT(_wcsicmp(pModule->ModuleName, BackupModuleName) == 0);

        Status = ElfpCloseLogFile(pModule->LogFile, ELF_LOG_CLOSE_BACKUP);

        UnlinkLogModule(pModule);
        DeleteAtom(pModule->ModuleAtom);

        //
        // NB : DO NOT decrement the logfile reference count - this has
        //      been done in ElfpCloseLogFile.
        //
        if (pModule->LogFile->RefCount == 0)
        {
            ELF_LOG1(TRACE,
                     "ElfrOpenBELW: Reference count for %ws log is 0 -- destroying\n",
                     pModule->ModuleName);

            UnlinkLogFile(pModule->LogFile); // Unlink the structure
            RtlDeleteResource ( &pModule->LogFile->Resource );
            RtlDeleteSecurityObject(&pModule->LogFile->Sd);
            ElfpFreeBuffer (pModule->LogFile->LogFileName);
            ElfpFreeBuffer (pModule->LogFile->LogModuleName);
            ElfpFreeBuffer (pModule->LogFile);
        }

        ElfpFreeBuffer(pModule->ModuleName);
        ElfpFreeBuffer(pModule);
    }

    return Status;
}


NTSTATUS
ElfrRegisterEventSourceW (
    IN  EVENTLOG_HANDLE_W   UNCServerName,
    IN  PRPC_UNICODE_STRING ModuleName,
    IN  PRPC_UNICODE_STRING RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrRegisterEventSourceW API.
  This routine allocates a structure for the context handle, finds
  the matching module name and fills in the data. It returns the
  pointer to the handle structure.


Arguments:

    UNCServerName   - Not used.

    ModuleName      - Name of the module that is making this call.

    RegModuleName   - Not used.

    MajorVersion/MinorVersion - The version of the client.

    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".

Note:

    For now, just call ElfpOpenELW.

--*/
{
    //
    // All arguments checked in ElfpOpenELW.
    //
    return ElfpOpenELW(UNCServerName,
                       ModuleName,
                       RegModuleName,
                       MajorVersion,
                       MinorVersion,
                       LogHandle,
                       ELF_LOGFILE_WRITE);
}


NTSTATUS
ElfrOpenELW (
    IN  EVENTLOG_HANDLE_W   UNCServerName,
    IN  PRPC_UNICODE_STRING ModuleName,
    IN  PRPC_UNICODE_STRING RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrOpenELW API.
  This routine allocates a structure for the context handle, finds
  the matching module name and fills in the data. It returns the
  pointer to the handle structure.


Arguments:

    UNCServerName   - Not used.

    ModuleName      - Name of the module that is making this call.

    RegModuleName   - Not used.

    MajorVersion/MinorVersion - The version of the client.


    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".


--*/
{
    //
    // All arguments checked in ElfpOpenELW.
    //

    return ElfpOpenELW(UNCServerName,
                       ModuleName,
                       RegModuleName,
                       MajorVersion,
                       MinorVersion,
                       LogHandle,
                       ELF_LOGFILE_READ);
}


NTSTATUS
ElfpOpenELW (
    IN  EVENTLOG_HANDLE_W   UNCServerName,
    IN  PRPC_UNICODE_STRING ModuleName,
    IN  PRPC_UNICODE_STRING RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle,
    IN  ULONG               DesiredAccess
    )

/*++

Routine Description:

  Looks alot like ElfrOpenELW but also gets passed a DesiredAccess.

Arguments:

    UNCServerName   - Not used.

    ModuleName      - Name of the module that is making this call.

    RegModuleName   - Not used.

    MajorVersion/MinorVersion - The version of the client.


    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

    DesiredAccess   - Indicates the access desired for this logfile.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".

--*/
{
    NTSTATUS        Status;
    PLOGMODULE      Module;
    IELF_HANDLE     LogIHandle;
    BOOL            ForSecurityLog = FALSE;

    //
    // Check arguments.
    //

    Status = VerifyUnicodeString(ModuleName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG0(ERROR,
                 "ElfpOpenELW: ModuleName is not a Unicode string\n");

        return Status;
    }

    if (LogHandle == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfpOpenELW: LogHandle is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // Allocate a new structure for the context handle
    //

    LogIHandle = (IELF_HANDLE) ElfpAllocateBuffer (
                                    sizeof (*LogIHandle)
                                  + ModuleName->Length
                                  + sizeof (WCHAR)
                                  );

    if (LogIHandle)
    {
        //
        // Find the module structure in order to pull out the Atom.
        //
        // GetModuleStruc *always* succeeds! (returns default if module
        // not found).
        //

        Module = GetModuleStruc((PUNICODE_STRING) ModuleName);

        //
        // Validate the caller has appropriate access to this logfile.
        // If this is the security log, then check privilege instead.
        //
        if (_wcsicmp(ELF_SECURITY_MODULE_NAME, Module->LogFile->LogModuleName->Buffer) == 0)
        {
            ELF_LOG0(TRACE,
                     "ElfpOpenELW: Opening Security log\n");

            ForSecurityLog = TRUE;
        }

        Status = ElfpAccessCheckAndAudit(
                     L"EventLog",            // SubSystemName
                     L"LogFile",             // ObjectTypeName
                     Module->ModuleName,     // ObjectName
                     LogIHandle,             // Context handle - required?
                     Module->LogFile->Sd,    // Security Descriptor
                     DesiredAccess,          // Requested Access
                     NULL,                   // GENERIC_MAPPING
                     ForSecurityLog);        // Indicates the check is for security log

        if (NT_SUCCESS(Status))
        {
            LogIHandle->Atom = Module->ModuleAtom;

            LogIHandle->NameLength = ModuleName->Length + sizeof(WCHAR);

            RtlCopyMemory(LogIHandle->Name, ModuleName->Buffer, ModuleName->Length);

            LogIHandle->Name[ModuleName->Length / sizeof(WCHAR)] = L'\0';

            LogIHandle->MajorVersion = MajorVersion; // Store the version
            LogIHandle->MinorVersion = MinorVersion; // of the client

            //
            // Initialize seek positions and flags to zero.
            //

            LogIHandle->SeekRecordPos    = 0;
            LogIHandle->SeekBytePos      = 0;
            LogIHandle->Flags            = 0;
            LogIHandle->dwNotifyRequests = 0;

            //
            // Link in this structure to the list of context handles
            //

            LogIHandle->Signature = ELF_CONTEXTHANDLE_SIGN; // DEBUG
            LinkContextHandle (LogIHandle);

            *LogHandle = LogIHandle;                // Set return handle
            Status = STATUS_SUCCESS;                // Set return status
        }
        else
        {
            ELF_LOG1(TRACE,
                     "ElfpOpenELW: ElfpAccessCheckAndAudit failed %#x\n",
                     Status);

            ElfpFreeBuffer(LogIHandle);
        }
    }
    else
    {
        ELF_LOG0(ERROR,
                 "ElfpOpenELW: Unable to allocate LogIHandle\n");

        Status = STATUS_NO_MEMORY;
    }

    return Status;

    UNREFERENCED_PARAMETER(UNCServerName);
    UNREFERENCED_PARAMETER(RegModuleName);
}


NTSTATUS
w_ElfrReadEL (
    IN      ULONG       Flags,                  // ANSI or UNICODE
    IN      IELF_HANDLE LogHandle,
    IN      ULONG       ReadFlags,
    IN      ULONG       RecordNumber,
    IN      ULONG       NumberOfBytesToRead,
    IN      PBYTE       Buffer,
    OUT     PULONG      NumberOfBytesRead,
    OUT     PULONG      MinNumberOfBytesNeeded
    )

/*++

Routine Description:

  This is the worker for the ElfrReadEL APIs.

Arguments:

   Same as ElfrReadELW API except that Flags contains an indication
   of whether this is ANSI or UNICODE.

Return Value:

    Same as the main API.

NOTES:

    We assume that the client-side has validated the flags to ensure that
    only one type of each bit is set. No checking is done at the server end.


--*/
{
    NTSTATUS            Status;
    PLOGMODULE          Module;
    ELF_REQUEST_RECORD  Request;
    READ_PKT            ReadPkt;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "w_ElfrReadEL: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Ensure the caller has read access.
    //

    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_READ))
    {
        ELF_LOG0(ERROR,
                 "w_ElfrReadEL: LogHandle does not have read access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //

    if (Buffer == NULL || !NumberOfBytesRead || !MinNumberOfBytesNeeded)
    {
        ELF_LOG1(ERROR,
                 "w_ElfrReadEL: %ws\n",
                 (Buffer == NULL ? L"Buffer is NULL" :
                      (!NumberOfBytesRead ? L"NumberOfBytesRead is 0" :
                                            L"MinNumberOfBytesNeeded is 0")));

        return STATUS_INVALID_PARAMETER;
    }

    //
    // The ELF_HANDLE_INVALID_FOR_READ flag bit would be set if the
    // file changed underneath this handle.
    //

    if (LogHandle->Flags & ELF_LOG_HANDLE_INVALID_FOR_READ)
    {
        ELF_LOG0(ERROR,
                 "w_ElfrReadEL: Logfile changed under this handle -- invalid for read\n");

        return STATUS_EVENTLOG_FILE_CHANGED;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //

    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "w_ElfrReadEL: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    Request.Pkt.ReadPkt = &ReadPkt; // Set up read packet in request packet

    //
    // Find the matching module structure
    //
    Module = FindModuleStrucFromAtom (LogHandle->Atom);

    //
    // Only continue if the module was found
    //

    if (Module != NULL)
    {
        ELF_LOG1(TRACE,
                 "w_ElfrReadEL: Performing read on module %ws\n",
                 Module->ModuleName);

        //
        // Fill in the request packet
        //
        Request.Module = Module;
        Request.Flags = 0;
        Request.LogFile = Module->LogFile;
        Request.Command = ELF_COMMAND_READ;
        Request.Status = STATUS_SUCCESS;

        Request.Pkt.ReadPkt->MinimumBytesNeeded = *MinNumberOfBytesNeeded;
        Request.Pkt.ReadPkt->BufferSize = NumberOfBytesToRead;
        Request.Pkt.ReadPkt->Buffer = (PVOID)Buffer;
        Request.Pkt.ReadPkt->ReadFlags = ReadFlags;
        Request.Pkt.ReadPkt->RecordNumber = RecordNumber;
        Request.Pkt.ReadPkt->LastSeekPos = LogHandle->SeekBytePos;
        Request.Pkt.ReadPkt->LastSeekRecord = LogHandle->SeekRecordPos;
        Request.Pkt.ReadPkt->Flags = Flags;     // Indicate UNICODE or ANSI

        //
        // Pass along whether the last read was in a forward or backward
        // direction (affects how we treat being at EOF). Then reset the
        // bit in the handle depending on what this read is.
        //
        if (LogHandle->Flags & ELF_LOG_HANDLE_LAST_READ_FORWARD)
        {
            Request.Pkt.ReadPkt->Flags |= ELF_LAST_READ_FORWARD;
        }

        if (ReadFlags & EVENTLOG_FORWARDS_READ)
        {
            LogHandle->Flags |= ELF_LOG_HANDLE_LAST_READ_FORWARD;
        }
        else
        {
            LogHandle->Flags &= ~(ELF_LOG_HANDLE_LAST_READ_FORWARD);
        }


        //
        // Perform the operation
        //
        ElfPerformRequest(&Request);

        //
        // Update current seek positions
        //
        LogHandle->SeekRecordPos = Request.Pkt.ReadPkt->LastSeekRecord;
        LogHandle->SeekBytePos   = Request.Pkt.ReadPkt->LastSeekPos;

        //
        // Set up return values
        //
        *NumberOfBytesRead      = Request.Pkt.ReadPkt->BytesRead;
        *MinNumberOfBytesNeeded = Request.Pkt.ReadPkt->MinimumBytesNeeded;

        Status = Request.Status;
    }
    else
    {
        ELF_LOG0(ERROR,
                 "w_ElfrReadEL: No module associated with atom in LogHandle\n");

        Status = STATUS_INVALID_HANDLE;

        //
        // Set the NumberOfBytesNeeded to zero since there are no bytes to
        // transfer.
        //
        *NumberOfBytesRead = 0;
        *MinNumberOfBytesNeeded = 0;
    }

    return Status;
}


NTSTATUS
ElfrReadELW (
    IN      IELF_HANDLE LogHandle,
    IN      ULONG       ReadFlags,
    IN      ULONG       RecordNumber,
    IN      ULONG       NumberOfBytesToRead,
    IN      PBYTE       Buffer,
    OUT     PULONG      NumberOfBytesRead,
    OUT     PULONG      MinNumberOfBytesNeeded
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrReadELW API.

Arguments:



Return Value:

    Returns an NTSTATUS code, NumberOfBytesRead if the read was successful
    and MinNumberOfBytesNeeded if the buffer was not big enough.


--*/
{
    //
    // Call the worker with the UNICODE flag.
    // All arguments checked in w_ElfrReadEL.
    //
    return w_ElfrReadEL(ELF_IREAD_UNICODE,
                        LogHandle,
                        ReadFlags,
                        RecordNumber,
                        NumberOfBytesToRead,
                        Buffer,
                        NumberOfBytesRead,
                        MinNumberOfBytesNeeded);
}


NTSTATUS
ElfrReportEventW (
    IN      IELF_HANDLE LogHandle,
    IN      ULONG               EventTime,
    IN      USHORT              EventType,
    IN      USHORT              EventCategory OPTIONAL,
    IN      ULONG               EventID,
    IN      USHORT              NumStrings,
    IN      ULONG               DataSize,
    IN      PRPC_UNICODE_STRING ComputerName,
    IN      PRPC_SID            UserSid,
    IN      PRPC_UNICODE_STRING Strings[],
    IN      PBYTE               Data,
    IN      USHORT              Flags,
    IN OUT  PULONG              RecordNumber OPTIONAL,
    IN OUT  PULONG              TimeWritten  OPTIONAL
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrReportEventW API.

Arguments:


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS            Status;
    PLOGMODULE          Module;
    ELF_REQUEST_RECORD  Request;
    WRITE_PKT           WritePkt;

    ULONG RecordLength;
    ULONG StringOffset, DataOffset;
    ULONG StringsSize;
    USHORT i;
    PVOID EventBuffer;
    PEVENTLOGRECORD EventLogRecord;
    PWSTR  ReplaceStrings, SrcString;
    PBYTE  BinaryData;
    PUNICODE_STRING  UComputerName;
    PWSTR   UModuleName;
    ULONG   PadSize;
    ULONG   UserSidLength = 0;              // Init to zero
    ULONG   UserSidOffset;
    ULONG   ModuleNameLen, ComputerNameLen; // Length in bytes
    ULONG   zero = 0;                       // For pad bytes
    LARGE_INTEGER    Time;
    ULONG   LogTimeWritten;

    //
    // These will be for Security Auditing to use for paired events.
    //
    UNREFERENCED_PARAMETER(RecordNumber);
    UNREFERENCED_PARAMETER(TimeWritten);

    //
    // Check the handle before proceeding.
    //
    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventW: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Insure the caller has write access.
    //

    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_WRITE))
    {
        ELF_LOG0(ERROR,
                 "ElfrReportEventW: LogHandle does not have write access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //
    Status = VerifyUnicodeString(ComputerName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventW: ComputerName is not a valid Unicode string %#x\n",
                 Status);

        return Status;
    }

    if (Strings == NULL && NumStrings != 0)
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventW: Strings is NULL and NumStrings is non-zero (%d)\n",
                 NumStrings);

        return STATUS_INVALID_PARAMETER;
    }

    //
    // This condition is TRUE iff a backup operator has opened the security
    // log. In this case deny access, since backup operators are allowed
    // only backup operation on the security log.
    //
    if (LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP)
    {
        ELF_LOG0(ERROR,
                 "ElfrReportEventW: Handle is a backup handle\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Make sure the SID passed in is valid
    //

    if (ARGUMENT_PRESENT(UserSid))
    {
        if (!IsValidSid(UserSid))
        {
            ELF_LOG0(ERROR,
                     "ElfrReportEventW: UserSid is invalid\n");

            return STATUS_INVALID_PARAMETER;
        }
    }

    //
    // Verify the string arguments
    //
    for (i = 0; i < NumStrings; i++ )
    {
        Status = VerifyUnicodeString(Strings[i]);

        if (!NT_SUCCESS(Status))
        {
            ELF_LOG2(ERROR,
                     "ElfrReportEventW: String %d is not a valid Unicode string %#x\n",
                     i,
                     Status);

            return STATUS_INVALID_PARAMETER;
        }
    }

    //
    // Can't write to a backup log
    //

    if (LogHandle->Flags & ELF_LOG_HANDLE_BACKUP_LOG)
    {
        ELF_LOG0(ERROR,
                 "ElfrReportEventW: Handle is for a backup log\n");

        return STATUS_INVALID_HANDLE;
    }

    //
    // Make sure they didn't pass in a null pointer for the data, but tell
    // me there was something there (I still think RPC should protect me from
    // this!)
    //
    if (!Data && DataSize != 0)
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventW: Data is NULL and DataSize is non-zero (%d)\n",
                 DataSize);

        return STATUS_INVALID_PARAMETER;
    }

    UComputerName = (PUNICODE_STRING)ComputerName;
    UModuleName   = LogHandle->Name;

    Request.Pkt.WritePkt = &WritePkt;   // Set up write packet in request packet
    Request.Flags = 0;

    //
    // Find the matching module structure
    //

    Module = FindModuleStrucFromAtom (LogHandle->Atom);

    if (Module != NULL)
    {
        //
        // Generate any additional information needed in the record.
        //
        // Info that we have                Info to generate
        // -----------------                ----------------
        //  Modulename                      UserSidLength
        //  EventType                       Length
        //  EventID                         StringOffset
        //  NumStrings                      DataOffset
        //  Strings                         PadBytes
        //  DataLength                      LogTimeWritten
        //  Data
        //  UserSidOffset
        //  UserSid
        //  ComputerName
        //  TimeGenerated
        //

        // LogTimeWritten
        // We need to generate a time when the log is written. This
        // gets written in the log so that we can use it to test the
        // retention period when wrapping the file.
        //

        NtQuerySystemTime(&Time);
        RtlTimeToSecondsSince1970(&Time,
                                  &LogTimeWritten);


        //
        // USERSIDLENTGH
        //
        if (UserSid)
        {
            UserSidLength = RtlLengthSid((PSID)UserSid);

            ELF_LOG1(TRACE,
                     "ElfrReportEventW: Length of sid is %d\n",
                     UserSidLength);
        }

        //
        // USERSIDOFFSET
        //
        // Extract the lengths from the STRING structure, and take care of
        // the trailing NULLs.
        //
        ModuleNameLen   = (wcslen(UModuleName) + 1) * sizeof (WCHAR);
        ComputerNameLen = UComputerName->Length + sizeof(WCHAR);

        ELF_LOG1(TRACE,
                 "ElfrReportEventW: Module name length (bytes) is %d\n",
                 ModuleNameLen);

        ELF_LOG1(TRACE,
                 "ElfrReportEventW: Computer name length (bytes) is %d\n",
                 UComputerName->Length + sizeof(WCHAR));

        UserSidOffset = sizeof(EVENTLOGRECORD) + ModuleNameLen + ComputerNameLen;
        UserSidOffset = ALIGN_UP_64(UserSidOffset, sizeof(PVOID));

        //
        // STRING OFFSET:
        //
        StringOffset = UserSidOffset + UserSidLength;

        //
        // Calculate the length of strings so that we can see how
        // much space is needed for that.
        //
        StringsSize = 0;

        for (i = 0; i < NumStrings; i++)
        {
            ELF_LOG3(TRACE,
                     "ElfrReportEventW: Length (bytes) of string %d (%ws) is %d\n",
                     i,
                     Strings[i]->Buffer,
                     Strings[i]->Length + sizeof(WCHAR));

            StringsSize += Strings[i]->Length + sizeof(WCHAR);
        }

        //
        // DATA OFFSET:
        //
        DataOffset = StringOffset + StringsSize;

        //
        // Determine how big a buffer is needed for the eventlog record.
        //
        RecordLength = DataOffset
                         + DataSize
                         + sizeof(RecordLength); // Size excluding pad bytes

        ELF_LOG1(TRACE,
                 "ElfrReportEventW: RecordLength (no pad bytes) is %d\n",
                 RecordLength);

        //
        // Determine how many pad bytes are needed to align to a DWORD
        // boundary.
        //

        PadSize = sizeof(ULONG) - (RecordLength % sizeof(ULONG));

        RecordLength += PadSize;    // True size needed

        ELF_LOG2(TRACE,
                 "ElfrReportEventW: RecordLength (with %d pad bytes) is %d\n",
                 PadSize,
                 RecordLength);

        //
        // Allocate the buffer for the Eventlog record
        //
        EventBuffer = ElfpAllocateBuffer(RecordLength);

        if (EventBuffer != NULL)
        {
            //
            // Fill up the event record
            //
            EventLogRecord = (PEVENTLOGRECORD)EventBuffer;

            EventLogRecord->Length = RecordLength;
            EventLogRecord->TimeGenerated = EventTime;
            EventLogRecord->Reserved  = ELF_LOG_FILE_SIGNATURE;
            EventLogRecord->TimeWritten = LogTimeWritten;
            EventLogRecord->EventID = EventID;
            EventLogRecord->EventType = EventType;
            EventLogRecord->EventCategory = EventCategory;
            EventLogRecord->ReservedFlags = Flags;
            EventLogRecord->ClosingRecordNumber = 0;
            EventLogRecord->NumStrings = NumStrings;
            EventLogRecord->StringOffset = StringOffset;
            EventLogRecord->DataLength = DataSize;
            EventLogRecord->DataOffset = DataOffset;
            EventLogRecord->UserSidLength = UserSidLength;
            EventLogRecord->UserSidOffset = UserSidOffset;

            //
            // Fill in the variable-length fields
            //

            //
            // STRINGS
            //
            ReplaceStrings = (PWSTR)((ULONG_PTR)EventLogRecord + (ULONG)StringOffset);

            for (i = 0; i < NumStrings; i++)
            {
                SrcString = (PWSTR) Strings[i]->Buffer;

                ELF_LOG1(TRACE,
                         "ElfrReportEventW: Copying string %d into record\n",
                         i);

                RtlCopyMemory(ReplaceStrings, SrcString, Strings[i]->Length);

                ReplaceStrings[Strings[i]->Length / sizeof(WCHAR)] = L'\0';
                ReplaceStrings = (PWSTR)((PBYTE) ReplaceStrings
                                                     + Strings[i]->Length
                                                     + sizeof(WCHAR));
            }

            //
            // MODULENAME
            //
            BinaryData = (PBYTE) EventLogRecord + sizeof(EVENTLOGRECORD);

            RtlCopyMemory(BinaryData,
                          UModuleName,
                          ModuleNameLen);

            ELF_LOG1(TRACE,
                     "ElfrReportEventW: Copying module name (%ws) into record\n",
                     UModuleName);

            //
            // COMPUTERNAME
            //
            ReplaceStrings = (LPWSTR) (BinaryData + ModuleNameLen);

            RtlCopyMemory(ReplaceStrings,
                          UComputerName->Buffer,
                          UComputerName->Length);

            ReplaceStrings[UComputerName->Length / sizeof(WCHAR)] = L'\0';

            ELF_LOG1(TRACE,
                     "ElfrReportEventW: Copying computer name (%ws) into record\n",
                     ReplaceStrings);

            //
            // USERSID
            //

            BinaryData = ((PBYTE) EventLogRecord) + UserSidOffset;

            RtlCopyMemory(BinaryData,
                          UserSid,
                          UserSidLength);

            //
            // BINARY DATA
            //
            BinaryData = (PBYTE) ((ULONG_PTR)EventLogRecord + DataOffset);

            if (Data)
            {
                RtlCopyMemory(BinaryData,
                              Data,
                              DataSize);
            }

            //
            // PAD  - Fill with zeros
            //
            BinaryData = (PBYTE) ((ULONG_PTR)BinaryData + DataSize);

            RtlCopyMemory(BinaryData,
                          &zero,
                          PadSize);

            //
            // LENGTH at end of record
            //
            BinaryData = (PBYTE)((ULONG_PTR) BinaryData + PadSize); // Point after pad bytes

            ((PULONG) BinaryData)[0] = RecordLength;

            //
            // Make sure we are in the right place
            //
            ASSERT ((ULONG_PTR)BinaryData
                == (RecordLength + (ULONG_PTR)EventLogRecord) - sizeof(ULONG));

            //
            // Set up request packet.
            // Link event log record into the request structure.
            //
            Request.Module = Module;
            Request.LogFile = Request.Module->LogFile;
            Request.Command = ELF_COMMAND_WRITE;

            Request.Pkt.WritePkt->Buffer = (PVOID)EventBuffer;
            Request.Pkt.WritePkt->Datasize = RecordLength;

            //
            // Perform the operation
            //
            ElfPerformRequest( &Request );

            //
            // Replicate the event if part of a cluster
            //
            ElfpReplicateEvent(Module, EventBuffer, RecordLength);

            //
            // Free up the buffer
            //
            ElfpFreeBuffer(EventBuffer);

            Status = Request.Status;                // Set status of WRITE
        }
        else
        {
            ELF_LOG0(ERROR,
                     "ElfrReportEventW: Unable to allocate EventLogRecord\n");

            Status = STATUS_NO_MEMORY;
        }

    }
    else
    {
        ELF_LOG0(ERROR,
                 "ElfrReportEventW: No module associated with atom in LogHandle\n");

        Status = STATUS_INVALID_HANDLE;
    }

    return Status;
}


//
// ANSI APIs
//

NTSTATUS
ElfrClearELFA (
    IN  IELF_HANDLE     LogHandle,
    IN  PRPC_STRING     BackupFileName
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrClearELFA API.

Arguments:

    LogHandle       - The context-handle for this module's call.

    BackupFileName  - Name of the file to back up the current log file.
                      NULL implies not to back up the file.


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS        Status;
    UNICODE_STRING  BackupFileNameU;

    //
    // Check the handle before proceeding.
    //
    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrClearELFA: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Ensure the caller has clear access.
    //
    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_CLEAR))
    {
        ELF_LOG0(ERROR,
                 "ElfrClearELFA: Handle doesn't have clear access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //

    Status = VerifyAnsiString((PANSI_STRING) BackupFileName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrClearELFA: BackupFileName is not a valid Ansi string %#x\n",
                 Status);

        return Status;
    }

    //
    // Convert the BackupFileName to a UNICODE STRING and call the
    // UNICODE API to do the work.
    //
    Status = RtlAnsiStringToUnicodeString((PUNICODE_STRING) &BackupFileNameU,
                                          (PANSI_STRING) BackupFileName,
                                          TRUE);

    if (NT_SUCCESS(Status))
    {
        Status = ElfrClearELFW(LogHandle,
                               (PRPC_UNICODE_STRING) &BackupFileNameU);

        RtlFreeUnicodeString (&BackupFileNameU);
    }
    else
    {
        ELF_LOG2(ERROR,
                 "ElfrClearELFA: Conversion of Ansi string %s to Unicode failed %#x\n",
                 BackupFileName->Buffer,
                 Status);
    }

    return Status;

}



NTSTATUS
ElfrBackupELFA (
    IN  IELF_HANDLE     LogHandle,
    IN  PRPC_STRING     BackupFileName
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrBackupELFA API.

Arguments:

    LogHandle       - The context-handle for this module's call.

    BackupFileName  - Name of the file to back up the current log file.


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS        Status;
    UNICODE_STRING  BackupFileNameU;

    //
    // Check the handle before proceeding.
    //

    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrBackupELFA: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Ensure the caller has backup access.
    //
    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_BACKUP))
    {
        ELF_LOG0(ERROR,
                 "ElfrBackupELFA: Handle does not have backup access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //
    Status = VerifyAnsiString((PANSI_STRING) BackupFileName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrBackupELFA: BackupFileName is not a valid Ansi string %#x\n",
                 Status);

        return Status;
    }

    //
    // Convert the BackupFileName to a UNICODE STRING and call the
    // UNICODE API to do the work.
    //
    Status = RtlAnsiStringToUnicodeString((PUNICODE_STRING) &BackupFileNameU,
                                          (PANSI_STRING) BackupFileName,
                                          TRUE);

    if (NT_SUCCESS(Status))
    {
        Status = ElfrBackupELFW(LogHandle,
                                (PRPC_UNICODE_STRING) &BackupFileNameU);

        RtlFreeUnicodeString(&BackupFileNameU);
    }
    else
    {
        ELF_LOG2(ERROR,
                 "ElfrBackupELFA: Conversion of Ansi string %s to Unicode failed %#x\n",
                 BackupFileName->Buffer,
                 Status);
    }

    return Status;

}


NTSTATUS
ElfrRegisterEventSourceA (
    IN  EVENTLOG_HANDLE_A   UNCServerName,
    IN  PRPC_STRING         ModuleName,
    IN  PRPC_STRING         RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrRegisterEventSourceA API.
  This routine allocates a structure for the context handle, finds
  the matching module name and fills in the data. It returns the
  pointer to the handle structure.


Arguments:

    UNCServerName   - Not used.

    ModuleName      - Name of the module that is making this call.

    RegModuleName   - Not used.

    MajorVersion/MinorVersion - The version of the client.


    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".

Note:

    For now, just call ElfrOpenELA.


--*/
{

    NTSTATUS Status;
    PLOGMODULE Module;
    UNICODE_STRING ModuleNameU;

    //
    // Check arguments.
    //
    // LogHandle check in ElfpOpenELA.
    //

    Status = VerifyAnsiString((PANSI_STRING) ModuleName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrRegisterEventSourceA: ModuleName is not a valid Ansi string %#x\n",
                 Status);

        return Status;
    }

    Status = RtlAnsiStringToUnicodeString((PUNICODE_STRING) &ModuleNameU,
                                          (PANSI_STRING) ModuleName,
                                          TRUE);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG2(ERROR,
                 "ElfrRegisterEventSourceA: Conversion of Ansi string %s "
                     "to Unicode failed %#x\n",
                 ModuleName->Buffer,
                 Status);

        return Status;
    }

    Module = GetModuleStruc((PUNICODE_STRING) &ModuleNameU);

    RtlFreeUnicodeString(&ModuleNameU);

    return ElfpOpenELA(UNCServerName,
                       ModuleName,
                       RegModuleName,
                       MajorVersion,
                       MinorVersion,
                       LogHandle,
                       ELF_LOGFILE_WRITE);
}

NTSTATUS
ElfrOpenELA (
    IN  EVENTLOG_HANDLE_A   UNCServerName,
    IN  PRPC_STRING         ModuleName,
    IN  PRPC_STRING         RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrOpenEL API.
  This routine allocates a structure for the context handle, finds
  the matching module name and fills in the data. It returns the
  pointer to the handle structure.


Arguments:

    UNCServerName   - Not used.

    ModuleName      - Name of the module that is making this call.

    RegModuleName   - Name of module to use to determine the log file.

    MajorVersion/MinorVersion - The version of the client.


    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".


--*/
{
    //
    // All arguments checked in ElfpOpenELA.
    //

    return ElfpOpenELA(UNCServerName,
                       ModuleName,
                       RegModuleName,
                       MajorVersion,
                       MinorVersion,
                       LogHandle,
                       ELF_LOGFILE_READ);
}


NTSTATUS
ElfpOpenELA (
    IN  EVENTLOG_HANDLE_A   UNCServerName,
    IN  PRPC_STRING         ModuleName,
    IN  PRPC_STRING         RegModuleName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle,
    IN  ULONG               DesiredAccess
    )

/*++

Routine Description:

  Looks alot loke ElfrOpenELA, only this also takes a DesiredAccess parameter.


Arguments:

    UNCServerName   - Not used.

    ModuleName      - Name of the module that is making this call.

    RegModuleName   - Name of module to use to determine the log file.

    MajorVersion/MinorVersion - The version of the client.


    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".

--*/
{
    NTSTATUS       Status;
    UNICODE_STRING ModuleNameU;

    //
    // Check arguments.
    //
    Status = VerifyAnsiString((PANSI_STRING) ModuleName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfpOpenELA: ModuleName is not a valid Ansi string %#x\n",
                 Status);

        return Status;
    }

    if (LogHandle == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfpOpenELA: LogHandle is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // Convert the ModuleName and RegModulename to UNICODE STRINGs and call
    // the UNICODE API to do the work.
    //

    Status = RtlAnsiStringToUnicodeString((PUNICODE_STRING) &ModuleNameU,
                                          (PANSI_STRING) ModuleName,
                                          TRUE);

    if (NT_SUCCESS(Status))
    {
        //
        // We *KNOW* that the UNCServerName is not used
        // by ElfpOpenELW so we save ourselves some work
        // and just pass in a NULL.
        //
        Status = ElfpOpenELW((EVENTLOG_HANDLE_W) NULL,
                             (PRPC_UNICODE_STRING) &ModuleNameU,
                             NULL,
                             MajorVersion,
                             MinorVersion,
                             LogHandle,
                             DesiredAccess);

        RtlFreeUnicodeString(&ModuleNameU);
    }
    else
    {
        ELF_LOG2(ERROR,
                 "ElfpOpenELA: Conversion of Ansi string %s to Unicode failed %#x\n",
                 ModuleName->Buffer,
                 Status);
    }

    return (Status);
    UNREFERENCED_PARAMETER(UNCServerName);
}


NTSTATUS
ElfrOpenBELA (
    IN  EVENTLOG_HANDLE_A   UNCServerName,
    IN  PRPC_STRING         FileName,
    IN  ULONG               MajorVersion,
    IN  ULONG               MinorVersion,
    OUT PIELF_HANDLE        LogHandle
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrOpenBEL API.
  This routine allocates a structure for the context handle, finds
  the matching module name and fills in the data. It returns the
  pointer to the handle structure.


Arguments:

    UNCServerName   - Not used.

    FileName        - Filename of the logfile

    MajorVersion/MinorVersion - The version of the client.

    LogHandle       - Pointer to the place where the pointer to the
                      context handle structure will be placed.

Return Value:

    Returns an NTSTATUS code and, if no error, a "handle".


--*/
{
    NTSTATUS        Status;
    UNICODE_STRING  FileNameU;

    //
    // Check arguments.
    //

    Status = VerifyAnsiString((PANSI_STRING) FileName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrOpenBELA: FileName is not a valid Ansi string %#x\n",
                 Status);

        return Status;
    }

    //
    // A filename must be specified.
    //
    if (FileName->Length == 0)
    {
        ELF_LOG0(ERROR,
                 "ElfrOpenBELA: Filename length is 0\n");

        return STATUS_INVALID_PARAMETER;
    }

    if (LogHandle == NULL)
    {
        ELF_LOG0(ERROR,
                 "ElfrOpenBELA: LogHandle is NULL\n");

        return STATUS_INVALID_PARAMETER;
    }

    //
    // Convert the FileName to a UNICODE STRINGs and call
    // the UNICODE API to do the work.
    //
    Status = RtlAnsiStringToUnicodeString((PUNICODE_STRING) &FileNameU,
                                          (PANSI_STRING) FileName,
                                          TRUE);

    if (NT_SUCCESS(Status))
    {
        //
        // We *KNOW* that the UNCServerName is not used
        // by ElfrOpenELW so we save ourselves some work
        // and just pass in a NULL.
        //
        Status = ElfrOpenBELW ((EVENTLOG_HANDLE_W) NULL,
                               (PRPC_UNICODE_STRING) &FileNameU,
                               MajorVersion,
                               MinorVersion,
                               LogHandle);

        RtlFreeUnicodeString(&FileNameU);
    }
    else
    {
        ELF_LOG2(ERROR,
                 "ElfrOpenBELA: Error converting Ansi string %s to Unicode %#x\n",
                 FileName->Buffer,
                 Status);
    }

    return Status;
    UNREFERENCED_PARAMETER(UNCServerName);

}



NTSTATUS
ElfrReadELA (
    IN      IELF_HANDLE LogHandle,
    IN      ULONG       ReadFlags,
    IN      ULONG       RecordNumber,
    IN      ULONG       NumberOfBytesToRead,
    IN      PBYTE       Buffer,
    OUT     PULONG      NumberOfBytesRead,
    OUT     PULONG      MinNumberOfBytesNeeded
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrReadEL API.

Arguments:



Return Value:

    Returns an NTSTATUS code, NumberOfBytesRead if the read was successful
    and MinNumberOfBytesNeeded if the buffer was not big enough.


--*/
{
    //
    // Call the worker with the ANSI flag.
    // All arguments checked in w_ElfrReadEL.
    //
    return w_ElfrReadEL(ELF_IREAD_ANSI,
                        LogHandle,
                        ReadFlags,
                        RecordNumber,
                        NumberOfBytesToRead,
                        Buffer,
                        NumberOfBytesRead,
                        MinNumberOfBytesNeeded);
}



NTSTATUS
ConvertStringArrayToUnicode (
    PUNICODE_STRING *pUStringArray,
    PANSI_STRING    *Strings,
    USHORT          NumStrings
    )

/*++

Routine Description:

  This routine takes an array of PANSI_STRINGs and generates an array of
  PUNICODE_STRINGs. The destination array has already been allocated
  by the caller, but the structures for the UNICODE_STRINGs will need
  to be allocated by this routine.

Arguments:

    pUStringArray   - Array of PUNICODE_STRINGs.
    Strings         - Array of PANSI_STRINGs.
    NumStrings      - Number of elements in the arrays.

Return Value:

    Returns an NTSTATUS code.

--*/
{
    NTSTATUS Status = STATUS_SUCCESS;
    USHORT   i;

    //
    // For each string passed in, allocate a UNICODE_STRING buffer
    // and set it to the UNICODE equivalent of the string passed in.
    //
    for (i = 0; i < NumStrings; i++)
    {
        if (Strings[i])
        {
            Status = VerifyAnsiString(Strings[i]);

            if (!NT_SUCCESS(Status))
            {
                ELF_LOG2(ERROR,
                         "ConvertStringArrayToUnicode: String %d is not "
                             "a valid Ansi string %#x\n",
                         i,
                         Status);

                break;
            }

            pUStringArray[i] = ElfpAllocateBuffer(sizeof(UNICODE_STRING));

            if (pUStringArray[i])
            {
                Status = RtlAnsiStringToUnicodeString(pUStringArray[i],
                                                      (PANSI_STRING) Strings[i],
                                                      TRUE);

                if (!NT_SUCCESS(Status))
                {
                    ELF_LOG2(ERROR,
                             "ConvertStringArrayToUnicode: Conversion of Ansi string "
                                 "%s to Unicode failed %#x\n",
                             Strings[i]->Buffer,
                             Status);
                }
            }
            else
            {
                ELF_LOG2(ERROR,
                         "ConvertStringArrayToUnicode: Unable to allocate memory for "
                             "Unicode string %d (Ansi string %s)\n",
                         i,
                         Strings[i]->Buffer);

                Status = STATUS_NO_MEMORY;
            }
        }
        else
        {
            pUStringArray[i] = NULL;
        }

        if (!NT_SUCCESS(Status))
        {
            break;                  // Jump out of loop and return status
        }
    }

    //
    // Free any allocations on failure.
    //

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ConvertStringArrayToUnicode: Function failed %#x\n",
                 Status);

        FreePUStringArray(pUStringArray, (USHORT)(i + 1));
    }

    return Status;
}



VOID
FreePUStringArray (
    PUNICODE_STRING  *pUStringArray,
    USHORT          NumStrings
    )
/*++

Routine Description:

  This routine takes the PUNICODE_STRING array that was filled in by
  ConvertStringArrayToUnicode and frees the buffer portion of
  each unicode string and then the UNICODE structure itseld. It handles
  the case where the array may not have been filled completely due
  to insufficient memory.

Arguments:

    pUStringArray   - Array of PUNICODE_STRINGs.
    NumStrings      - Number of elements in the array.

Return Value:

    NONE.

--*/
{
    USHORT      i;

    for (i = 0; i < NumStrings; i++)
    {
        if (pUStringArray[i])
        {
            if (pUStringArray[i]->Buffer)
            {
                //
                // Free the string buffer
                //
                RtlFreeUnicodeString(pUStringArray[i]);
            }

            //
            // Free the UNICODE_STRING itself -- this may be allocated
            // even if the string buffer isn't (if RtlAnsiStringToUnicodeString
            // failed in the ConvertStringArrayToUnicode call)
            //
            ElfpFreeBuffer(pUStringArray[i]);
            pUStringArray[i] = NULL;
        }
    }
}



NTSTATUS
ElfrReportEventA (
    IN      IELF_HANDLE         LogHandle,
    IN      ULONG               Time,
    IN      USHORT              EventType,
    IN      USHORT              EventCategory OPTIONAL,
    IN      ULONG               EventID,
    IN      USHORT              NumStrings,
    IN      ULONG               DataSize,
    IN      PRPC_STRING         ComputerName,
    IN      PRPC_SID            UserSid,
    IN      PRPC_STRING         Strings[],
    IN      PBYTE               Data,
    IN      USHORT              Flags,
    IN OUT  PULONG              RecordNumber OPTIONAL,
    IN OUT  PULONG              TimeWritten OPTIONAL
    )

/*++

Routine Description:

  This is the RPC server entry point for the ElfrReportEventA API.

Arguments:


Return Value:

    Returns an NTSTATUS code.


--*/
{
    NTSTATUS            Status;
    UNICODE_STRING      ComputerNameU;
    PUNICODE_STRING     *pUStringArray = NULL;

    //
    // Check the handle before proceeding.
    //
    Status = VerifyElfHandle(LogHandle);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventA: VerifyElfHandle failed %#x\n",
                 Status);

        return Status;
    }

    //
    // Ensure the caller has write access.
    //
    if (!(LogHandle->GrantedAccess & ELF_LOGFILE_WRITE))
    {
        ELF_LOG0(ERROR,
                 "ElfrReportEventA: Handle doesn't have write access\n");

        return STATUS_ACCESS_DENIED;
    }

    //
    // Verify additional arguments.
    //
    Status = VerifyAnsiString((PANSI_STRING) ComputerName);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventA: ComputerName is not a valid Ansi string %#x\n",
                 Status);

        return Status;
    }

    if (Strings == NULL && NumStrings != 0)
    {
        ELF_LOG1(ERROR,
                 "ElfrReportEventA: Strings is NULL and NumStrings is non-zero (%d)\n",
                 NumStrings);

        return STATUS_INVALID_PARAMETER;
    }

    //
    // Convert the ComputerName to a UNICODE STRING and call the
    // UNICODE API.
    //
    Status = RtlAnsiStringToUnicodeString((PUNICODE_STRING) &ComputerNameU,
                                          (PANSI_STRING) ComputerName,
                                          TRUE);

    if (NT_SUCCESS(Status))
    {
        if (NumStrings)
        {
            pUStringArray = ElfpAllocateBuffer(NumStrings * sizeof(PUNICODE_STRING));

            if (pUStringArray)
            {
                //
                // Convert the array of STRINGs to an array of UNICODE-STRINGs
                // before calling the unicode API.
                // We can just use the array of Strings passed in since we
                // don't need to use it anywhere else.
                //
                Status = ConvertStringArrayToUnicode(pUStringArray,
                                                     (PANSI_STRING *) Strings,
                                                     NumStrings);
            }
            else
            {
                ELF_LOG0(ERROR,
                         "ElfrReportEventA: Unable to allocate pUStringArray\n");

                Status = STATUS_NO_MEMORY;
            }
        }

        if (NT_SUCCESS(Status))
        {
            Status = ElfrReportEventW(LogHandle,
                                      Time,
                                      EventType,
                                      EventCategory,
                                      EventID,
                                      NumStrings,
                                      DataSize,
                                      (PRPC_UNICODE_STRING) &ComputerNameU,
                                      UserSid,
                                      (PRPC_UNICODE_STRING*) pUStringArray,
                                      Data,
                                      Flags,        // Flags        | paired event
                                      RecordNumber, // RecordNumber | support. not in
                                      TimeWritten); // TimeWritten  | product 1

            FreePUStringArray(pUStringArray, NumStrings);
        }

        RtlFreeUnicodeString(&ComputerNameU);
    }
    else
    {
        ELF_LOG2(ERROR,
                 "ElfrReportEventA: Conversion of Ansi string %s to Unicode failed %#X\n",
                 ComputerName->Buffer,
                 Status);
    }

    ElfpFreeBuffer(pUStringArray);

    return Status;
}


NTSTATUS
VerifyElfHandle(
    IN IELF_HANDLE LogHandle
    )

/*++

Routine Description:

    Verify the handle via its DWORD signature.

Arguments:

    LogHandle   - Handle to verify.

Return Value:

    STATUS_SUCCESS          - Presumably valid handle.
    STATUS_INVALID_HANDLE   - Invalid handle.

--*/
{
    NTSTATUS Status;

    if (LogHandle != NULL)
    {
        try
        {
            if (LogHandle->Signature == ELF_CONTEXTHANDLE_SIGN)
            {
                Status = STATUS_SUCCESS;
            }
            else
            {
                ELF_LOG2(ERROR,
                         "VerifyElfHandle: Incorrect LogHandle signature %#x "
                             "(should be %#x)\n",
                         LogHandle->Signature,
                         ELF_CONTEXTHANDLE_SIGN);

                Status = STATUS_INVALID_HANDLE;
            }
        }
        except(EXCEPTION_EXECUTE_HANDLER)
        {
            ELF_LOG1(ERROR,
                     "VerifyElfHandle: Exception %#x caught while probing LogHandle\n",
                     GetExceptionCode());

            Status = STATUS_INVALID_HANDLE;
        }
    }
    else
    {
        ELF_LOG0(ERROR,
                 "VerifyElfHandle: LogHandle is NULL\n");

        Status = STATUS_INVALID_HANDLE;
    }

    return Status;
}


ULONG
Safewcslen(
    UNALIGNED WCHAR *p,
    LONG            MaxLength
    )
/*++

    Safewcslen - Strlen that won't exceed MaxLength

Routine Description:

    This routine is called to determine the size of a UNICODE_STRING

Arguments:
    p         - The string to count.
    MaxLength - The maximum length to look at.


Return Value:

    Number of bytes in the string (or MaxLength)

--*/
{
    ULONG Count = 0;

    if (p)
    {
        while (MaxLength > 0 && *p++ != UNICODE_NULL)
        {
            MaxLength -= sizeof(WCHAR);
            Count     += sizeof(WCHAR);
        }
    }

    return Count;
}


ULONG
Safestrlen(
    UNALIGNED char *p,
    LONG           MaxLength
    )
/*++

    Safestrlen - Strlen that won't exceed MaxLength

Routine Description:

    This routine is called to determine the length of an ANSI_STRING

Arguments:
    p         - The string to count.
    MaxLength - The maximum length to look at.


Return Value:

    Number of chars in the string (or MaxLength)

--*/
{
    ULONG Count = 0;

    if (p)
    {
        while (MaxLength > 0 && *p++ != '\0')
        {
            MaxLength--;
            Count++;
        }
    }

    return Count;
}



NTSTATUS
VerifyUnicodeString(
    IN PUNICODE_STRING pUString
    )

/*++

Routine Description:

    Verify the unicode string. The string is invalid if:
        The UNICODE_STRING structure ptr is NULL.
        The MaximumLength field is invalid (too small).
        The Length field is incorrect.

Arguments:

    pUString    - String to verify.

Return Value:

    STATUS_SUCCESS              - Valid string.
    STATUS_INVALID_PARAMETER    - I wonder.

--*/
{
    NTSTATUS Status = STATUS_SUCCESS;

    //
    // Check validity of structure fields and actual string
    // length vs. length value supplied
    //
    if (!pUString ||
        pUString->MaximumLength < pUString->Length ||
        pUString->Length != Safewcslen(pUString->Buffer,
                                       pUString->MaximumLength))
    {
        ELF_LOG1(ERROR,
                 "VerifyUnicodeString: String is invalid because %ws\n",
                 (!pUString ?
                     L"it's NULL" :
                     (pUString->MaximumLength < pUString->Length ? L"MaximumLength < Length" :
                                                                   L"Length is incorrect")));

        Status = STATUS_INVALID_PARAMETER;
    }

    return Status;
}



NTSTATUS
VerifyAnsiString(
    IN PANSI_STRING pAString
    )

/*++

Routine Description:

    Verify the ansi string. The string is invalid if:
        The ANSI_STRING structure ptr is NULL.
        The MaximumLength field is invalid (too small).
        The Length field is incorrect.

Arguments:

    pAString    - String to verify.

Return Value:

    STATUS_SUCCESS              - Valid string.
    STATUS_INVALID_PARAMETER    - I wonder.

--*/
{
    NTSTATUS Status = STATUS_SUCCESS;

    if (!pAString ||
        pAString->MaximumLength < pAString->Length ||
        pAString->Length != Safestrlen(pAString->Buffer,
                                       pAString->MaximumLength))
    {
        ELF_LOG1(ERROR,
                 "VerifyAnsiString: String is invalid because %ws\n",
                 (!pAString ?
                     L"it's NULL" :
                     (pAString->MaximumLength < pAString->Length ? L"MaximumLength < Length" :
                                                                   L"Length is incorrect")));

        Status = STATUS_INVALID_PARAMETER;
    }

    return Status;
}



//SS:changes made to enable cluster wide event logging
/****
@func       NTSTATUS | ElfrRegisterClusterSvc|  This is the server entrypoint
            for ElfRegisterClusterSvc.  The cluster service registers
            itself with the event log service to enable propagation of events
            across the cluster.  The binding handle to the cluster service for
            propagation of events is obtained.

@parm       IN  EVENTLOG_HANDLE_W | UNCServerName | This parameter is ignored. It
            is retained for correspondence with other elf apis.

@parm       OUT PULONG | pulSize | A pointer to a long where the size of the
            packed event information structure is returned.

@parm       OUT PBYTE | *ppPackedEventInfo| A pointer to the packed event information
            structure for propagation is returned via this parameter.

@comm       The cluster service propagates events contained in this structure
            and deletes the memory after it has done so.  Once the cluster service has
            registered with the eventlog service, the eventlog service passes up
            logged events to the cluster service for propagation.

@rdesc      Returns a result code. ERROR_SUCCESS on success.

@xref       <f ElfRegisterClusterSvc> <f ElfrDeregisterClusterSvc>
****/
NTSTATUS
ElfrRegisterClusterSvc(
    IN  EVENTLOG_HANDLE_W UNCServerName,
    OUT PULONG            pulSize,
    OUT PBYTE             *ppPackedEventInfo)
{
    ULONG               ulTotalSize       = 0;
    ULONG               ulTotalEventsSize = 0;
    ULONG               ulNumLogFiles     = 0;
    PPROPLOGFILEINFO    pPropLogFileInfo  = NULL;
    NTSTATUS            Status;
    PPACKEDEVENTINFO    pPackedEventInfo  = NULL;
    UINT                i;
    PEVENTSFORLOGFILE   pEventsForLogFile;
    WCHAR               *pBinding         = NULL;
    HANDLE              hClusSvcNode      = NULL;
    UNICODE_STRING      RootRegistryNode;
    OBJECT_ATTRIBUTES   ObjectAttributes;
    BOOL                bAcquired = FALSE;
    BOOL                bInitedCritSec    = FALSE;

    ELF_LOG0(CLUSTER,
             "ElfRegisterClusterSvc: Entry\n");

    //
    // Initialize the OUT parameters
    //
    *pulSize = 0;
    *ppPackedEventInfo = NULL;

    //
    // Check to see if the cluster service is installed.
    //
    RtlInitUnicodeString(&RootRegistryNode, REG_CLUSSVC_NODE_PATH);
    InitializeObjectAttributes(&ObjectAttributes,
                               &RootRegistryNode,
                               OBJ_CASE_INSENSITIVE,
                               NULL,
                               NULL);

    Status = NtOpenKey(&hClusSvcNode, KEY_READ | KEY_NOTIFY, &ObjectAttributes);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG2(ERROR,
                 "ElfRegisterClusterSvc: NtOpenKey of %ws failed %#x\n",
                 REG_CLUSSVC_NODE_PATH,
                 Status);

        goto FnExit;
    }

    NtClose(hClusSvcNode);

    Status = STATUS_SUCCESS;

    //
    // If the cluster service dies and restarts again in the same session
    // then it will try to register again.
    // We dont reinitialize these globals again to prevent leaks
    //
    RtlEnterCriticalSection(&gClPropCritSec);

    if (!gbClustering)
    {
        ELF_LOG0(CLUSTER,
                 "ElfRegisterClusterSvc: gbClustering is FALSE\n");

        //
        // Load the cluster support dll
        //
        ghClusDll = LoadLibraryW(L"CLUSSPRT.DLL");

        if (!ghClusDll)
        {
            RtlLeaveCriticalSection(&gClPropCritSec);
            Status = STATUS_DLL_NOT_FOUND;
            goto FnExit;
        }
    }
    //
    // Get the function entry points
    //
    gpfnPropagateEvents   = (PROPAGATEEVENTSPROC) GetProcAddress(ghClusDll,
                                                                 "PropagateEvents");

    gpfnBindToCluster     = (BINDTOCLUSTERPROC) GetProcAddress(ghClusDll,
                                                               "BindToClusterSvc");

    gpfnUnbindFromCluster = (UNBINDFROMCLUSTERPROC) GetProcAddress(ghClusDll,
                                                                   "UnbindFromClusterSvc");


    if (!gpfnPropagateEvents || !gpfnBindToCluster || !gpfnUnbindFromCluster)
    {
        ELF_LOG1(ERROR,
                 "ElfRegisterClusterSvc: GetProcAddress for %ws in clussprt.dll failed\n",
                 (!gpfnPropagateEvents ? L"PropagateEvents" :
                                         (!gpfnBindToCluster ? L"BindToClusterSvc" :
                                                               L"UnbindFromClusterSvc")));

        RtlLeaveCriticalSection(&gClPropCritSec);
        Status = STATUS_PROCEDURE_NOT_FOUND;
        goto FnExit;
    }

    //
    // If we had bound to the cluster service previously, unbind and then rebind
    //
    if (ghCluster)
    {
        (*gpfnUnbindFromCluster)(ghCluster);
    }
    //
    // Bind to the cluster service
    //
    ghCluster = (*gpfnBindToCluster)(NULL);

    if (!ghCluster)
    {
        ELF_LOG1(ERROR,
                 "ElfRegisterClusterSvc: BindToCluster failed %d\n",
                 GetLastError());

        RtlLeaveCriticalSection(&gClPropCritSec);
        Status = STATUS_UNSUCCESSFUL;
        goto FnExit;
    }

    RtlLeaveCriticalSection(&gClPropCritSec);

    //
    // Since we are going to read the logs, make sure the service is running
    //
    while((GetElState() == RUNNING) && (!bAcquired))
    {

        bAcquired = RtlAcquireResourceShared(&GlobalElfResource,
                                             FALSE);             // Don't wait

        if (!bAcquired)
        {
            ELF_LOG0(CLUSTER,
                     "ElfRegisterClusterSvc: Sleep waiting for global resource\n");

            Sleep(ELF_GLOBAL_RESOURCE_WAIT);
        }
    }

    //
    // If the resource was not available and the status of the service
    // changed to one of the "non-working" states, then we just return
    // unsuccesful.  Rpc should not allow this to happen.
    //
    if (!bAcquired)
    {
        ELF_LOG0(ERROR,
                 "ElfRegisterClusterSvc: Global resource not acquired\n");

        Status = STATUS_UNSUCCESSFUL;
        goto FnExit;
    }

    //
    // Determine the size of and acquire read locks on all files.
    // FindSizeofEventsSinceStart acquires the per-log locks if
    // there are events in that log to propagate.
    //
    Status = FindSizeofEventsSinceStart(&ulTotalEventsSize,
                                        &ulNumLogFiles,
                                        &pPropLogFileInfo);

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfRegisterClusterSvc: FindSizeofEventsSinceStart failed %#x\n",
                 Status);

        goto FnExit;
    }

    //
    // If there are any events to propagate
    //
    if (ulNumLogFiles && ulTotalEventsSize && pPropLogFileInfo)
    {
        ulTotalSize = sizeof(PACKEDEVENTINFO)                          // header
                          + (sizeof(ULONG) * ulNumLogFiles)            // offsets
                          + (sizeof(EVENTSFORLOGFILE) * ulNumLogFiles) // info per log
                          + ulTotalEventsSize;

        //
        // Allocate memory
        //
        *ppPackedEventInfo = (PBYTE) ElfpAllocateBuffer(ulTotalSize);

        if (!(*ppPackedEventInfo))
        {
            ELF_LOG1(ERROR,
                     "ElfRegisterClusterSvc: Unable to allocate %d bytes for pPackedEventInfo\n",
                     ulTotalSize);

            //
            // Free the read locks acquired in FindSizeofEventsSinceStart
            //
            for (i=0;i<ulNumLogFiles;i++)
            {
                RtlReleaseResource(&(pPropLogFileInfo[i].pLogFile->Resource));
            }

            Status = STATUS_NO_MEMORY;
            goto FnExit;
        }

        pPackedEventInfo = (PPACKEDEVENTINFO)(*ppPackedEventInfo);

        ELF_LOG2(CLUSTER,
                 "ElfRegisterClusterSvc: Allocated %d bytes, pPackedEventInfo is %#x\n",
                 ulTotalSize,
                 pPackedEventInfo);

        pPackedEventInfo->ulNumEventsForLogFile = ulNumLogFiles;

        for (i = 0;i < ulNumLogFiles; i++)
        {
            //
            // Set the offsets to the EVENTSFORLOGFILE structures
            //
            pPackedEventInfo->ulOffsets[i] =
                ((i == 0) ? (sizeof(PACKEDEVENTINFO) + ulNumLogFiles * sizeof(ULONG)) :
                            (pPackedEventInfo->ulOffsets[i - 1]
                                 + (pPropLogFileInfo[i - 1].ulTotalEventSize
                                 + sizeof(EVENTSFORLOGFILE))));

            ELF_LOG2(CLUSTER,
                     "ElfRegisterClusterSvc: pPackedEventInfo->ulOffsets[%d] = %d\n",
                     i,
                     pPackedEventInfo->ulOffsets[i]);

            pEventsForLogFile = (PEVENTSFORLOGFILE) ((PBYTE) pPackedEventInfo
                                                         + pPackedEventInfo->ulOffsets[i]);

            //
            // Set the size of the ith EVENTSFORLOGFILE structure
            //
            pEventsForLogFile->ulSize = sizeof(EVENTSFORLOGFILE)
                                            + pPropLogFileInfo[i].ulTotalEventSize;

            //
            // Copy the file name (or should we get the module name?)
            //
            lstrcpyW(pEventsForLogFile->szLogicalLogFile,
                     pPropLogFileInfo[i].pLogFile->LogModuleName->Buffer);

            //
            // Set the number of events
            //
            pEventsForLogFile->ulNumRecords = pPropLogFileInfo[i].ulNumRecords;

            ELF_LOG3(CLUSTER,
                     "ElfRegisterClusterSvc: pEventsForLogFile struct -- ulSize = %d, "
                         "Logical file = %ws, ulNumRecords = %d\n",
                     pEventsForLogFile->ulSize,
                     pEventsForLogFile->szLogicalLogFile,
                     pEventsForLogFile->ulNumRecords);

            //
            // Get the events
            //
            Status = GetEventsToProp((PEVENTLOGRECORD) ((PBYTE) pEventsForLogFile
                                                            + sizeof(EVENTSFORLOGFILE)),
                                                        pPropLogFileInfo + i);

            //
            // If that fails, set the ulNumRecords to 0 so tha
            // on a write this data is discarded.
            //
            if (!NT_SUCCESS(Status))
            {
                ELF_LOG2(ERROR,
                         "ElfRegisterClusterSvc: GetEventsToProp for %ws log failed %#x\n",
                         pPropLogFileInfo[i].pLogFile->LogModuleName->Buffer,
                         Status);

                pEventsForLogFile->ulNumRecords=0;

                //
                // Reset the error -- we will go to the next file
                //
                Status = STATUS_SUCCESS;
            }

            //
            // Advance the startpointer for all the files so if the cluster service
            // dies and is restarted, these events won't be propagated again
            //
            pPropLogFileInfo[i].pLogFile->SessionStartRecordNumber =
                pPropLogFileInfo[i].pLogFile->CurrentRecordNumber;

            ELF_LOG1(CLUSTER,
                     "ElfRegisterClusterSvc: Done processing %ws log\n",
                     pPropLogFileInfo[i].pLogFile->LogModuleName->Buffer);

            RtlReleaseResource (&(pPropLogFileInfo[i].pLogFile->Resource));
        }

        //
        // Set the total size
        //
        pPackedEventInfo->ulSize = pPackedEventInfo->ulOffsets[ulNumLogFiles - 1]
                                       + pPropLogFileInfo[ulNumLogFiles - 1].ulTotalEventSize
                                       + sizeof(EVENTSFORLOGFILE);

        *pulSize = pPackedEventInfo->ulSize;
    }

    RtlEnterCriticalSection (&gClPropCritSec);

    //
    // If the cluster service hadnt registered before or glClPackedEventInfo is NULL
    //
    if (!gbClustering || !gpClPackedEventInfo)
    {
        //
        // Allocate memory for processing events for propagation
        //
        ulTotalSize = sizeof(PACKEDEVENTINFO)              // header
                          + (sizeof(ULONG) * 1)            // offsets
                          + (sizeof(EVENTSFORLOGFILE) * 1) // per-log info
                          + MAXSIZE_OF_EVENTSTOPROP;

        //
        // Allocate memory
        //
        gpClPackedEventInfo = (PPACKEDEVENTINFO) ElfpAllocateBuffer(ulTotalSize);

        if (!gpClPackedEventInfo)
        {
            ELF_LOG1(ERROR,
                     "ElfRegisterClusterSvc: Unable to allocate %d bytes "
                         "for gpClPackedEventInfo\n",
                     ulTotalSize);

            Status = STATUS_NO_MEMORY;
            RtlLeaveCriticalSection (&gClPropCritSec);
            goto FnExit;
        }

        //
        // Setup the PACKEDEVENTINFO
        //
        gpClPackedEventInfo->ulNumEventsForLogFile = 1;
        gpClPackedEventInfo->ulOffsets[0]= sizeof(PACKEDEVENTINFO) + sizeof(ULONG);
    }

    //
    // Set the flag to true so that propagation is now on.
    //
    gbClustering = TRUE;
    RtlLeaveCriticalSection (&gClPropCritSec);

FnExit:

    if (!NT_SUCCESS(Status))
    {
        //
        // Something went wrong
        //
        ELF_LOG1(ERROR,
                 "ElfRegisterClusterSvc: Exiting with error %#x\n",
                 Status);

        RtlEnterCriticalSection(&gClPropCritSec);

        ElfpFreeBuffer(gpClPackedEventInfo);
        gpClPackedEventInfo = NULL;

        if (ghCluster && gpfnUnbindFromCluster)
        {
            (*gpfnUnbindFromCluster)(ghCluster);
            ghCluster = NULL;
        }

        if (ghClusDll)
        {
            FreeLibrary(ghClusDll);
            ghClusDll = NULL;
        }

        RtlLeaveCriticalSection(&gClPropCritSec);
    }

    //
    // Free the pPropLogFileInfo stucture
    //
    ElfpFreeBuffer(pPropLogFileInfo);

    if (bAcquired)
    {
        ReleaseGlobalResource();
    }

    ELF_LOG1(CLUSTER,
             "ElfRegisterClusterSvc: Returning status %#x\n",
             Status);

    ELF_LOG2(CLUSTER,
             "ElfRegisterClusterSvc: *pulSize = %d, *ppPackedEventInfo = %#x\n",
             *pulSize,
             *ppPackedEventInfo);

    return Status;
}



/****
@func       NTSTATUS | ElfrDeregisterClusterSvc| This is the server entry point
            for ElfDeregisterClusterSvc().  Before shutdown the cluster
            service deregisters itself for propagation of events from the
            eventlog service.

@comm       Note that events logged after the cluster service goes down
            are not propagated.  Binding handle is freed.

@rdesc      Returns a result code. ERROR_SUCCESS on success.

@xref       <f ElfrRegisterClusterSvc>
****/
NTSTATUS
ElfrDeregisterClusterSvc(
    IN EVENTLOG_HANDLE_W UNCServerName
    )
{
    ELF_LOG0(CLUSTER,
             "ElfDeregisterClusterSvc: ElfrDeregisterClusterSvc: Entry\n");

    RtlEnterCriticalSection (&gClPropCritSec);

    if (gbClustering)
    {
        gbClustering = FALSE;

        ElfpFreeBuffer(gpClPackedEventInfo);
        gpClPackedEventInfo = NULL;

        //
        // Unload the cluster support dll
        //
        if (ghCluster && gpfnUnbindFromCluster)
        {
            (*gpfnUnbindFromCluster)(ghCluster);
            ghCluster = NULL;
        }

        if (ghClusDll)
        {
            FreeLibrary(ghClusDll);
            ghClusDll = NULL;
        }
    }

    RtlLeaveCriticalSection (&gClPropCritSec);

    ELF_LOG0(CLUSTER,
             "ElfDeregisterClusterSvc: Exit\n");

    return STATUS_SUCCESS;
}



/****
@func   NTSTATUS | ElfrWriteClusterEvents| The cluster service calls this
        api to log events reported at other nodes of the cluster in the event log files.

@parm   IN EVENTLOG_HANDLE_W | UNCServerName | Not used.

@parm   IN ULONG | ulSize | The size of the    packed event information structure.

@parm   IN PBYTE | pPackedEventInfo| A pointer to the packed event information
        structure for propagation.

@comm   The pPackedEventInfo is delinearized into eventlogbuffers for different event
        log files and the events are recorded in the appropriate eventlog file.  Multiple
        events per log file are supported.

@rdesc  Returns a result code. ERROR_SUCCESS on success.

@xref
****/
NTSTATUS
ElfrWriteClusterEvents(
    IN EVENTLOG_HANDLE_W UNCServerName,
    IN ULONG             ulSize,
    IN BYTE              *pBuffer
    )
{
    UINT                i,j;
    PEVENTSFORLOGFILE   pEventsForLogFile;
    UNICODE_STRING      ModuleName;
    PLOGMODULE          pLogModule;
    PEVENTLOGRECORD     pEventLogRecord;
    ELF_REQUEST_RECORD  Request;
    PPACKEDEVENTINFO    pPackedEventInfo;
    NTSTATUS            Status = STATUS_SUCCESS;
    WRITE_PKT           WritePkt;
    HANDLE              hClientToken = NULL;
    BOOL                bCheckMember;

    //
    // Impersonate to figure if the caller is in the admin group.
    // The cluster service must run in an account that has local
    // Admin privileges
    //
    Status = I_RpcMapWin32Status(RpcImpersonateClient(NULL));

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrWriteClusterEvents: RpcImpersonateClient failed %#x\n",
                 Status);

        goto FnExit;
    }


    if (!OpenThreadToken(GetCurrentThread(), TOKEN_READ, TRUE, &hClientToken))
    {
        ELF_LOG1(ERROR,
                 "ElfrWriteClusterEvents: OpenThreadToken failed %d\n",
                 GetLastError());

        RpcRevertToSelf();
        Status = STATUS_ACCESS_DENIED;
        goto FnExit;
    }

    if (!CheckTokenMembership(hClientToken,
                              ElfGlobalData->AliasAdminsSid,
                              &bCheckMember))
    {
        ELF_LOG1(ERROR,
                 "ElfrWriteClusterEvents: CheckTokenMembership failed %d\n",
                 GetLastError());

        RpcRevertToSelf();
        Status = STATUS_ACCESS_DENIED;
        goto FnExit;
    }

    if (!bCheckMember)
    {
        ELF_LOG0(ERROR,
                 "ElfrWriteClusterEvents: Caller is not an Admin\n");

        Status = STATUS_ACCESS_DENIED;
        RpcRevertToSelf();
        goto FnExit;
    }

    //
    // Stop impersonating
    //
    Status = I_RpcMapWin32Status(RpcRevertToSelf());

    if (!NT_SUCCESS(Status))
    {
        ELF_LOG1(ERROR,
                 "ElfrWriteClusterEvents: RpcRevertToSelf failed %#x\n",
                 Status);

        goto FnExit;
    }

    //
    // We want to put this in a try/except block because we're
    // probing potentially bad user-supplied data.
    //
    try
    {
        pPackedEventInfo = (PPACKEDEVENTINFO)pBuffer;

        
        //
        // Validate input parameters and check that clustering is on
        //
        if (!pPackedEventInfo
             ||
            !ulSize
             ||
            (((PBYTE)pPackedEventInfo + sizeof(PACKEDEVENTINFO)) > (PBYTE)(pBuffer + ulSize))
             ||
             ((PBYTE)pPackedEventInfo + ulSize <= pBuffer)   //if ulSize is large to cause overflow 
             ||
            (pPackedEventInfo->ulSize != ulSize)
             ||
            (!gbClustering))
        {
            ELF_LOG1(ERROR,
                     "ElfrWriteClusterEvents: Invalid parameter passed in -- %ws\n",
                     (!pPackedEventInfo ?
                          L"pPackedEventInfo is NULL" :
                          (!ulSize ?
                               L"ulSize is 0" :
                               (!gbClustering ?
                                    L"gbClustering is FALSE" :
                                    (pPackedEventInfo->ulSize != ulSize ?
                                         L"ulSize mismatch" :
                                         L"pBuffer too small or ulSize too large")))));

            Status = STATUS_INVALID_PARAMETER;
            goto FnExit;
        }

        ELF_LOG2(CLUSTER,
                 "ElfrWriteClusterEvents: ulSize = %d, ulNumEventsForLogFile = %d\n",
                 ulSize,
                 pPackedEventInfo->ulNumEventsForLogFile);


        if ((((PBYTE)pPackedEventInfo + sizeof(PACKEDEVENTINFO) + 
            (sizeof(DWORD) * (pPackedEventInfo->ulNumEventsForLogFile))) < 
            (PBYTE)(pBuffer)) ||
            (((PBYTE)pPackedEventInfo + sizeof(PACKEDEVENTINFO) + 
            (sizeof(DWORD) * (pPackedEventInfo->ulNumEventsForLogFile))) < 
            (PBYTE)(pBuffer + sizeof(PACKEDEVENTINFO))))                 
        {
            ELF_LOG0(ERROR,
                     "ElfrWriteClusterEvents: Buffer/values passed in caused overflow\n");
            Status = STATUS_INVALID_PARAMETER;                     
            goto FnExit;
        }

        //check to see whether we have valid offsets for each eventlog file in the buffer
        //first check to see the buffer passed in is big enough to contain the offsets
        if (((PBYTE)pPackedEventInfo + sizeof(PACKEDEVENTINFO) + 
            (sizeof(DWORD) * (pPackedEventInfo->ulNumEventsForLogFile))) > 
            (PBYTE)(pBuffer + ulSize))
        {
            ELF_LOG0(ERROR,
                     "ElfrWriteClusterEvents: Buffer passed in doesnt contain offsets for all the eventlogfiles\n");
            Status = STATUS_INVALID_PARAMETER;
            goto FnExit;
        }
        //
        // Setup the request packet
        //
        Request.Pkt.WritePkt = &WritePkt;   // Set up write packet in request packet
        Request.Flags = 0;

        //
        // For each log
        //
        for (i = 0; i < pPackedEventInfo->ulNumEventsForLogFile; i++)
        {
            pEventsForLogFile = (PEVENTSFORLOGFILE) ((PBYTE)pPackedEventInfo +
                                                         pPackedEventInfo->ulOffsets[i]);

            //
            // Check for overflow or pointer past end of buffer
            //
            if (((PBYTE) pEventsForLogFile < pBuffer)
                   ||
                (((PBYTE) pEventsForLogFile + sizeof(EVENTSFORLOGFILE)) >
                       (PBYTE) (pBuffer + ulSize)))
            {
                ELF_LOG2(ERROR,
                         "ElfrWriteClusterEvents: Bad offset for log %d -- %ws\n",
                         i,
                         ((PBYTE) pEventsForLogFile < pBuffer ? L"offset caused overflow" :
                                                                L"offset past end of buffer"));

                Status = STATUS_INVALID_PARAMETER;
                goto FnExit;
            }

            ELF_LOG2(CLUSTER,
                     "ElfrWriteClusterEvents: szLogicalFile = %ws, ulNumRecords = %d\n",
                     pEventsForLogFile->szLogicalLogFile,
                     pEventsForLogFile->ulNumRecords);

            //
            // Find the module -- since we dont trust this string, force null termination
            //
            pEventsForLogFile->szLogicalLogFile[MAXLOGICALLOGNAMESIZE - 1] = L'\0';

            RtlInitUnicodeString(&ModuleName, pEventsForLogFile->szLogicalLogFile);
            pLogModule = GetModuleStruc(&ModuleName);

            if (!pLogModule)
            {
                ELF_LOG1(ERROR,
                     "ElfrWriteClusterEvents: Bogus ModuleName %ws passed in\n",
                     pEventsForLogFile->szLogicalLogFile);
                //skip this log file and go to the next one                     
                continue;                                     
            }
            

            //
            // GetModuleStruc always returns something non-NULL -- if the
            // given module name is bogus, we'll use the Application log.
            //
            ELF_LOG2(CLUSTER,
                     "ElfrWriteClusterEvents: Processing records for %ws module (%ws log)\n",
                     pLogModule->ModuleName,
                     pLogModule->LogFile->LogModuleName->Buffer);

            Request.Module  = pLogModule;
            Request.LogFile = Request.Module->LogFile;
            Request.Command = ELF_COMMAND_WRITE;
            pEventLogRecord = (PEVENTLOGRECORD) (pEventsForLogFile->pEventLogRecords);

            for (j = 0;
                 j < pEventsForLogFile->ulNumRecords &&
                     pEventLogRecord->Reserved == ELF_LOG_FILE_SIGNATURE;
                 j++)
            {
                //
                // Check for pointer past end of buffer
                //
                if (((PBYTE) pEventLogRecord + pEventLogRecord->Length) >
                        (PBYTE) (pBuffer + ulSize))
                {
                    ELF_LOG3(ERROR,
                             "ElfrWriteClusterEvents: Record %d for %ws module "
                                 "(%ws log) too long\n",
                             j,
                             pLogModule->ModuleName,
                             pLogModule->LogFile->LogModuleName->Buffer);

                    Status = STATUS_INVALID_PARAMETER;
                    goto FnExit;
                }

                //
                // Fill in a request packet for the current record
                //
                Request.Pkt.WritePkt->Buffer   = pEventLogRecord;
                Request.Pkt.WritePkt->Datasize = pEventLogRecord->Length;

                //
                // SS: Should we get exclusive access to the log so that
                //     the current record number is not incremented
                //     for an event that needs to be propagated
                //     before the session start record number is set here?
                //
                ElfPerformRequest(&Request);

                //
                // Advance the session start record number, so that
                // we don't propagate an event propagated to us
                //
                pLogModule->LogFile->SessionStartRecordNumber =
                    pLogModule->LogFile->CurrentRecordNumber;

                //
                // Extract status of operation from the request packet
                //
                Status = Request.Status;

                if (!NT_SUCCESS(Status))
                {
                    ELF_LOG3(ERROR,
                             "ElfrWriteClusterEvents: Failed to write record %d to "
                                 "%ws log %#x\n",
                             j,
                             pLogModule->LogFile->LogModuleName->Buffer,
                             Status);
                }

                pEventLogRecord = (PEVENTLOGRECORD) ((PBYTE) pEventLogRecord +
                                                          pEventLogRecord->Length);
            }
        }
    }
    except (EXCEPTION_EXECUTE_HANDLER)
    {
        ELF_LOG1(ERROR,
                 "ElfrWriteClusterEvents: Exception %#x caught probing passed-in buffer\n",
                 GetExceptionCode());

        Status = STATUS_INVALID_PARAMETER;
    }

FnExit:

    if (hClientToken)
    {
        CloseHandle(hClientToken);
    }

    return Status;
}

/****
@func   NTSTATUS | ElfpReplicateEvent| The cluster service calls this
        api to log events reported at other nodes of the cluster in the event log files.

@parm   IN PLOGMODULE | pModule| A pointer to a module for the eventlog file.

@parm   IN PVOID | pEventBuffer | A pointer to the event buffer.

@parm   IN DWORD | dwRecordLength| The length of the event buffer in bytes.

@comm   This replicates an event log record across a cluster.

@rdesc  Returns a result code. ERROR_SUCCESS on success.

@xref
****/
NTSTATUS
ElfpReplicateEvent(
    IN PLOGMODULE   pModule,
    IN PVOID        pEventBuffer,
    IN DWORD        dwRecordLength
)
{
    DWORD               dwError = ERROR_SUCCESS;

    if (dwRecordLength >= MAXSIZE_OF_EVENTSTOPROP )
    {
        ELF_LOG0(TRACE,
                 "ElfpReplicateEvent: eventlog record size is bigger than supported size\n");
        return(dwError);
    }
    
    //
    // Acquire the critical section for this global propagation area
    //
    RtlEnterCriticalSection (&gClPropCritSec);

    if (gbClustering)
    {
        PEVENTSFORLOGFILE   pEventsForLogFile;

        ELF_LOG0(TRACE,
                 "ElfpReplicateEvent: Part of a cluster -- propagating the event\n");

        //
        // Packed event info consists of:
        //
        //    1. PACKEDEVENTINFO structure
        //    2. size of offsets (currently 1 -- sizeof(ULONG))
        //    3. EVENTSFORLOGFILE structure
        //    4. The record itself
        //
        gpClPackedEventInfo->ulSize = sizeof(PACKEDEVENTINFO)
                                          + sizeof(ULONG)
                                          + sizeof(EVENTSFORLOGFILE)
                                          + dwRecordLength;

        pEventsForLogFile =
            (PEVENTSFORLOGFILE)((PBYTE) gpClPackedEventInfo
                                            + gpClPackedEventInfo->ulOffsets[0]);

        //
        // Set the events for log file structure
        //
        pEventsForLogFile->ulNumRecords = 1;

        lstrcpyW(pEventsForLogFile->szLogicalLogFile,
                 pModule->LogFile->LogModuleName->Buffer);

        pEventsForLogFile->ulSize = sizeof(EVENTSFORLOGFILE)
                                        + dwRecordLength;

        RtlCopyMemory(pEventsForLogFile->pEventLogRecords,
                      (PVOID) pEventBuffer,
                      dwRecordLength);

        dwError = (*gpfnPropagateEvents)(ghCluster,
                                         gpClPackedEventInfo->ulSize,
                                         (PUCHAR) gpClPackedEventInfo);

        //
        // Advance the session start record number so that the same
        // record doesnt get propagated twice.  If the service restarts,
        // don't advance the session number if the call doesn't succeed.
        //
        // Issue:  If the server is multi-threaded, we might lose events
        //         if a latter one gets propagated before one that gets
        //         written to the log earlier.  I dont think this is an
        //         eventlog problem since we are calling in a CS
        //
        if (dwError == ERROR_SUCCESS)
        {
            pModule->LogFile->SessionStartRecordNumber =
                pModule->LogFile->CurrentRecordNumber;
        }
    }

    RtlLeaveCriticalSection (&gClPropCritSec);

    return(dwError);
}

//SS:end of changes made to enable cluster wide event logging