NT4/private/windows/base/server/srvatom.c

/*++

Copyright (c) 1990  Microsoft Corporation

Module Name:

    srvatom.c

Abstract:

    This file contains the Global Atom manager API routines

Author:

    Steve Wood (stevewo) 29-Oct-1990

Revision History:

--*/

#include "basesrv.h"

//
// Pointer to User function that returns a pointer to the
// global atom table associated with the windowstation
// userd by the specified thread.
//

NTSTATUS (*_UserGetGlobalAtomTable)(
    HANDLE hThread,
    PVOID *GlobalAtomTable
    );

//
// Pointer to User function that sets a pointer to the
// global atom table into the windowstation associated
// with the specified thread.
//

NTSTATUS (*_UserSetGlobalAtomTable)(
    HANDLE hThread,
    PVOID GlobalAtomTable
    );

NTSTATUS
BaseSrvGetGlobalAtomTable(
    PVOID *GlobalAtomTable
    )
{
    STRING ProcedureName;
    ANSI_STRING DllName;
    UNICODE_STRING DllName_U;
    HANDLE UserServerModuleHandle;
    static BOOL fInit = FALSE;
    NTSTATUS Status;

    if ( _UserGetGlobalAtomTable == NULL ) {

        if ( fInit == TRUE ) {

            //
            // If the exported atom routines cannot be found, deny access
            //

            return( STATUS_ACCESS_DENIED );
            }

        fInit = TRUE;

        //
        // Load pointers to the functions in winsrv.dll
        //

        RtlInitAnsiString( &DllName, "winsrv" );
        RtlAnsiStringToUnicodeString( &DllName_U, &DllName, TRUE );
        Status = LdrGetDllHandle(
                    UNICODE_NULL,
                    NULL,
                    &DllName_U,
                    (PVOID *)&UserServerModuleHandle
                    );

        RtlFreeUnicodeString( &DllName_U );

        if ( NT_SUCCESS(Status) ) {

                //
                // Now get the routined to query and set the 
                // atom table pointer.
                //

                RtlInitString( &ProcedureName, "_UserGetGlobalAtomTable" );
                Status = LdrGetProcedureAddress(
                                (PVOID)UserServerModuleHandle,
                                &ProcedureName,
                                0L,
                                (PVOID *)&_UserGetGlobalAtomTable
                                );

                RtlInitString( &ProcedureName, "_UserSetGlobalAtomTable" );
                Status = LdrGetProcedureAddress(
                                (PVOID)UserServerModuleHandle,
                                &ProcedureName,
                                0L,
                                (PVOID *)&_UserSetGlobalAtomTable
                                );
        }

        //
        // Deny access upon failure
        //

        if ( !NT_SUCCESS(Status) )
            return( STATUS_ACCESS_DENIED );
    }

    Status = (*_UserGetGlobalAtomTable)(
            CSR_SERVER_QUERYCLIENTTHREAD()->ThreadHandle,
            GlobalAtomTable);
    if ( !NT_SUCCESS(Status) ) {
        return Status;
        }
    
    //
    // Lock the heap until the call is complete.
    //

    RtlLockHeap( BaseSrvHeap );

    //
    // If there is an atom table, return it.
    //

    if ( *GlobalAtomTable ) {
        return STATUS_SUCCESS;
        }

    Status =  BaseRtlCreateAtomTable( 37,
                                      (USHORT)~MAXINTATOM,
                                      GlobalAtomTable
                                      );

    if ( NT_SUCCESS(Status) ) {
        Status = (*_UserSetGlobalAtomTable)(
                CSR_SERVER_QUERYCLIENTTHREAD()->ThreadHandle,
                *GlobalAtomTable);
        if ( !NT_SUCCESS(Status) ) {
            BaseRtlDestroyAtomTable( *GlobalAtomTable );
            }
        }

    if ( !NT_SUCCESS(Status) ) {
        RtlUnlockHeap( BaseSrvHeap );
        }

    return Status;
}

ULONG
BaseSrvDestroyGlobalAtomTable(
    IN OUT PCSR_API_MSG m,
    IN OUT PCSR_REPLY_STATUS ReplyStatus
    )
{
    PBASE_DESTROYGLOBALATOMTABLE_MSG a = (PBASE_DESTROYGLOBALATOMTABLE_MSG)&m->u.ApiMessageData;

    return BaseRtlDestroyAtomTable(a->GlobalAtomTable);
}

ULONG
BaseSrvGlobalAddAtom(
    IN OUT PCSR_API_MSG m,
    IN OUT PCSR_REPLY_STATUS ReplyStatus
    )
{
    PBASE_GLOBALATOMNAME_MSG a = (PBASE_GLOBALATOMNAME_MSG)&m->u.ApiMessageData;
    PVOID GlobalAtomTable;
    NTSTATUS Status;
    UNICODE_STRING AtomName;

    AtomName = a->AtomName;
    if (a->AtomNameInClient) {
        AtomName.Buffer = RtlAllocateHeap( BaseSrvHeap,
                                           MAKE_TAG( TMP_TAG ),
                                           AtomName.Length
                                         );
        if (AtomName.Buffer == NULL) {
            return (ULONG)STATUS_NO_MEMORY;
            }

        Status = NtReadVirtualMemory( CSR_SERVER_QUERYCLIENTTHREAD()->Process->ProcessHandle,
                                      a->AtomName.Buffer,
                                      AtomName.Buffer,
                                      AtomName.Length,
                                      NULL
                                    );
        }
    else {
        Status = STATUS_SUCCESS;
        }

    if (NT_SUCCESS( Status )) {
        Status = BaseSrvGetGlobalAtomTable(&GlobalAtomTable);
        if (NT_SUCCESS( Status )) {
            Status = BaseRtlAddAtomToAtomTable( GlobalAtomTable,
                                                &AtomName,
                                                NULL,
                                                &a->Atom
                                              );
            RtlUnlockHeap( BaseSrvHeap );
            }
        }

    if (a->AtomNameInClient) {
        RtlFreeHeap( BaseSrvHeap, 0, AtomName.Buffer );
        }

    return( (ULONG)Status );
    ReplyStatus;    // get rid of unreferenced parameter warning message
}


ULONG
BaseSrvGlobalFindAtom(
    IN OUT PCSR_API_MSG m,
    IN OUT PCSR_REPLY_STATUS ReplyStatus
    )
{
    PBASE_GLOBALATOMNAME_MSG a = (PBASE_GLOBALATOMNAME_MSG)&m->u.ApiMessageData;
    PVOID GlobalAtomTable;
    UNICODE_STRING AtomName;
    NTSTATUS Status;

    AtomName = a->AtomName;
    if (a->AtomNameInClient) {
        AtomName.Buffer = RtlAllocateHeap( BaseSrvHeap,
                                           MAKE_TAG( TMP_TAG ),
                                           AtomName.Length
                                         );
        if (AtomName.Buffer == NULL) {
            return (ULONG)STATUS_NO_MEMORY;
            }

        Status = NtReadVirtualMemory( CSR_SERVER_QUERYCLIENTTHREAD()->Process->ProcessHandle,
                                      a->AtomName.Buffer,
                                      AtomName.Buffer,
                                      AtomName.Length,
                                      NULL
                                    );
        }
    else {
        Status = STATUS_SUCCESS;
        }

    if (NT_SUCCESS( Status )) {
        Status = BaseSrvGetGlobalAtomTable(&GlobalAtomTable);
        if (NT_SUCCESS( Status )) {
            Status = BaseRtlLookupAtomInAtomTable( GlobalAtomTable,
                                                   &AtomName,
                                                   NULL,
                                                   &a->Atom
                                                 );
            RtlUnlockHeap( BaseSrvHeap );
            }
        }

    if (a->AtomNameInClient) {
        RtlFreeHeap( BaseSrvHeap, 0, AtomName.Buffer );
        }

    return( (ULONG)Status );
    ReplyStatus;    // get rid of unreferenced parameter warning message
}

ULONG
BaseSrvGlobalDeleteAtom(
    IN OUT PCSR_API_MSG m,
    IN OUT PCSR_REPLY_STATUS ReplyStatus
    )
{
    PBASE_GLOBALDELETEATOM_MSG a = (PBASE_GLOBALDELETEATOM_MSG)&m->u.ApiMessageData;
    PVOID GlobalAtomTable;
    NTSTATUS Status;

    Status = BaseSrvGetGlobalAtomTable(&GlobalAtomTable);
    if (NT_SUCCESS( Status )) {
        Status = BaseRtlDeleteAtomFromAtomTable( GlobalAtomTable,
                                                 a->Atom
                                               );
        RtlUnlockHeap( BaseSrvHeap );
        }

    return( (ULONG)Status );
    ReplyStatus;    // get rid of unreferenced parameter warning message
}

ULONG
BaseSrvGlobalGetAtomName(
    IN OUT PCSR_API_MSG m,
    IN OUT PCSR_REPLY_STATUS ReplyStatus
    )
{
    PBASE_GLOBALATOMNAME_MSG a = (PBASE_GLOBALATOMNAME_MSG)&m->u.ApiMessageData;
    UNICODE_STRING AtomName;
    PVOID GlobalAtomTable;
    NTSTATUS Status;

    AtomName = a->AtomName;
    if (a->AtomNameInClient) {
        AtomName.Buffer = RtlAllocateHeap( BaseSrvHeap,
                                           MAKE_TAG( TMP_TAG ),
                                           AtomName.MaximumLength
                                         );
        if (AtomName.Buffer == NULL) {
            return (ULONG)STATUS_NO_MEMORY;
            }
        }

    Status = BaseSrvGetGlobalAtomTable(&GlobalAtomTable);
    if (NT_SUCCESS( Status )) {
        Status = BaseRtlQueryAtomInAtomTable( GlobalAtomTable,
                                              a->Atom,
                                              &AtomName,
                                              NULL,
                                              NULL
                                            );

        a->AtomName.Length = AtomName.Length;
        if (NT_SUCCESS( Status ) && a->AtomNameInClient) {
            Status = NtWriteVirtualMemory( CSR_SERVER_QUERYCLIENTTHREAD()->Process->ProcessHandle,
                                           a->AtomName.Buffer,
                                           AtomName.Buffer,
                                           AtomName.Length,
                                           NULL
                                         );
            }
        RtlUnlockHeap( BaseSrvHeap );
        }

    if (a->AtomNameInClient) {
        RtlFreeHeap( BaseSrvHeap, 0, AtomName.Buffer );
        }

    return( (ULONG)Status );
    ReplyStatus;    // get rid of unreferenced parameter warning message
}