reg.c

winNT技术操作系统,国外开放的原代码和LIUX一样

        do
        {
            delKeys = CONTAINING_RECORD(delQueueHead.Flink,
                                        REGP_DEL_KEYS,
                                        ListEntry);

            BufferSize = 0;
            BasicInfo = NULL;
            newDelKeys = NULL;

ReadFirstSubKey:
            /* check if this key contains subkeys and delete them first by queuing
               them at the head of the list */
            Status2 = NtEnumerateKey(delKeys->KeyHandle,
                                     0,
                                     KeyBasicInformation,
                                     BasicInfo,
                                     BufferSize,
                                     &BufferSize);

            if (NT_SUCCESS(Status2))
            {
                OBJECT_ATTRIBUTES ObjectAttributes;
                UNICODE_STRING SubKeyName;
                
                ASSERT(newDelKeys != NULL);
                ASSERT(BasicInfo != NULL);

                /* don't use RtlInitUnicodeString as the string is not NULL-terminated! */
                SubKeyName.Length = BasicInfo->NameLength;
                SubKeyName.MaximumLength = BasicInfo->NameLength;
                SubKeyName.Buffer = BasicInfo->Name;

                InitializeObjectAttributes(&ObjectAttributes,
                                           &SubKeyName,
                                           OBJ_CASE_INSENSITIVE,
                                           delKeys->KeyHandle,
                                           NULL);

                /* open the subkey */
                Status2 = NtOpenKey(&newDelKeys->KeyHandle,
                                    DELETE | KEY_ENUMERATE_SUB_KEYS,
                                    &ObjectAttributes);
                if (!NT_SUCCESS(Status2))
                {
                    goto SubKeyFailure;
                }

                /* enqueue this key to the head of the deletion queue */
                InsertHeadList(&delQueueHead,
                               &newDelKeys->ListEntry);

                /* try again from the head of the list */
                continue;
            }
            else
            {
                if (Status2 == STATUS_BUFFER_TOO_SMALL)
                {
                    newDelKeys = RtlAllocateHeap(ProcessHeap,
                                                 0,
                                                 BufferSize + sizeof(REGP_DEL_KEYS));
                    if (newDelKeys != NULL)
                    {
                        BasicInfo = (PKEY_BASIC_INFORMATION)(newDelKeys + 1);

                        /* try again */
                        goto ReadFirstSubKey;
                    }
                    else
                    {
                        /* don't break, let's try to delete as many keys as possible */
                        Status2 = STATUS_INSUFFICIENT_RESOURCES;
                        goto SubKeyFailureNoFree;
                    }
                }
                else if (Status2 == STATUS_BUFFER_OVERFLOW)
                {
                    PREG_DEL_KEYS newDelKeys2;

                    ASSERT(newDelKeys != NULL);

                    /* we need more memory to query the key name */
                    newDelKeys2 = RtlReAllocateHeap(ProcessHeap,
                                                    0,
                                                    newDelKeys,
                                                    BufferSize + sizeof(REGP_DEL_KEYS));
                    if (newDelKeys2 != NULL)
                    {
                        newDelKeys = newDelKeys2;
                        BasicInfo = (PKEY_BASIC_INFORMATION)(newDelKeys + 1);

                        /* try again */
                        goto ReadFirstSubKey;
                    }
                    else
                    {
                        /* don't break, let's try to delete as many keys as possible */
                        Status2 = STATUS_INSUFFICIENT_RESOURCES;
                    }
                }
                else if (Status2 == STATUS_NO_MORE_ENTRIES)
                {
                    /* in some race conditions where another thread would delete
                       the same tree at the same time, newDelKeys could actually
                       be != NULL! */
                    if (newDelKeys != NULL)
                    {
                        RtlFreeHeap(ProcessHeap,
                                    0,
                                    newDelKeys);
                    }
                    break;
                }

SubKeyFailure:
                /* newDelKeys can be NULL here when NtEnumerateKey returned an
                   error other than STATUS_BUFFER_TOO_SMALL or STATUS_BUFFER_OVERFLOW! */
                if (newDelKeys != NULL)
                {
                    RtlFreeHeap(ProcessHeap,
                                0,
                                newDelKeys);
                }

SubKeyFailureNoFree:
                /* don't break, let's try to delete as many keys as possible */
                if (NT_SUCCESS(Status))
                {
                    Status = Status2;
                }
            }

            Status2 = NtDeleteKey(delKeys->KeyHandle);
            
            /* NOTE: do NOT close the handle anymore, it's invalid already! */

            if (!NT_SUCCESS(Status2))
            {
                /* close the key handle so we don't leak handles for keys we were
                   unable to delete. But only do this for handles not supplied
                   by the caller! */

                if (delKeys->KeyHandle != hKey)
                {
                    NtClose(delKeys->KeyHandle);
                }

                if (NT_SUCCESS(Status))
                {
                    /* don't break, let's try to delete as many keys as possible */
                    Status = Status2;
                }
            }
            
            /* remove the entry from the list */
            RemoveEntryList(&delKeys->ListEntry);

            RtlFreeHeap(ProcessHeap,
                        0,
                        delKeys);
        } while (!IsListEmpty(&delQueueHead));
    }
    else
        Status = STATUS_INSUFFICIENT_RESOURCES;

    return Status;
}


/************************************************************************
 *  RegDeleteTreeW
 *
 * @implemented
 */
LONG STDCALL
RegDeleteTreeW(IN HKEY hKey,
               IN LPCWSTR lpSubKey  OPTIONAL)
{
    HANDLE KeyHandle, CurKey, SubKeyHandle = NULL;
    NTSTATUS Status;

    Status = MapDefaultKey(&KeyHandle,
                           hKey);
    if (!NT_SUCCESS(Status))
    {
        return RtlNtStatusToDosError(Status);
    }

    if (lpSubKey != NULL)
    {
        OBJECT_ATTRIBUTES ObjectAttributes;
        UNICODE_STRING SubKeyName;

        RtlInitUnicodeString(&SubKeyName,
                             (LPWSTR)lpSubKey);

        InitializeObjectAttributes(&ObjectAttributes,
                                   &SubKeyName,
                                   OBJ_CASE_INSENSITIVE,
                                   KeyHandle,
                                   NULL);

        Status = NtOpenKey(&SubKeyHandle,
                           DELETE | KEY_ENUMERATE_SUB_KEYS,
                           &ObjectAttributes);
        if (!NT_SUCCESS(Status))
        {
            goto Cleanup;
        }
        
        CurKey = SubKeyHandle;
    }
    else
        CurKey = KeyHandle;

    Status = RegpDeleteTree(CurKey);

    if (NT_SUCCESS(Status))
    {
        /* make sure we only close hKey (KeyHandle) when the caller specified a
           subkey, because the handle would be invalid already! */
        if (CurKey != KeyHandle)
        {
            ClosePredefKey(KeyHandle);
        }
        
        return ERROR_SUCCESS;
    }
    else
    {
        /* make sure we close all handles we created! */
        if (SubKeyHandle != NULL)
        {
            NtClose(SubKeyHandle);
        }

Cleanup:
        ClosePredefKey(KeyHandle);
        
        return RtlNtStatusToDosError(Status);
    }
}


/************************************************************************
 *  RegDeleteTreeA
 *
 * @implemented
 */
LONG STDCALL
RegDeleteTreeA(IN HKEY hKey,
               IN LPCSTR lpSubKey  OPTIONAL)
{
    UNICODE_STRING SubKeyName = {0};
    LONG Ret;

    if (lpSubKey != NULL &&
        !RtlCreateUnicodeStringFromAsciiz(&SubKeyName,
                                          (LPSTR)lpSubKey))
    {
        return ERROR_NOT_ENOUGH_MEMORY;
    }

    Ret = RegDeleteTreeW(hKey,
                         SubKeyName.Buffer);

    RtlFreeUnicodeString(&SubKeyName);

    return Ret;
}


/************************************************************************
 *  RegDisableReflectionKey
 *
 * @unimplemented
 */
LONG WINAPI
RegDisableReflectionKey(IN HKEY hBase)
{
    DPRINT1("RegDisableReflectionKey(0x%p) UNIMPLEMENTED!\n", hBase);
    return ERROR_CALL_NOT_IMPLEMENTED;
}


/************************************************************************
 *  RegEnableReflectionKey
 *
 * @unimplemented
 */
LONG WINAPI
RegEnableReflectionKey(IN HKEY hBase)
{
    DPRINT1("RegEnableReflectionKey(0x%p) UNIMPLEMENTED!\n", hBase);
    return ERROR_CALL_NOT_IMPLEMENTED;
}

/******************************************************************************
 * RegpApplyRestrictions   [internal]
 *
 * Helper function for RegGetValueA/W.
 */
static VOID
RegpApplyRestrictions( DWORD dwFlags, DWORD dwType, DWORD cbData,
                       PLONG ret )
{
    /* Check if the type is restricted by the passed flags */
    if (*ret == ERROR_SUCCESS || *ret == ERROR_MORE_DATA)
    {
        DWORD dwMask = 0;

        switch (dwType)
        {
        case REG_NONE: dwMask = RRF_RT_REG_NONE; break;
        case REG_SZ: dwMask = RRF_RT_REG_SZ; break;
        case REG_EXPAND_SZ: dwMask = RRF_RT_REG_EXPAND_SZ; break;
        case REG_MULTI_SZ: dwMask = RRF_RT_REG_MULTI_SZ; break;
        case REG_BINARY: dwMask = RRF_RT_REG_BINARY; break;
        case REG_DWORD: dwMask = RRF_RT_REG_DWORD; break;
        case REG_QWORD: dwMask = RRF_RT_REG_QWORD; break;
        }

        if (dwFlags & dwMask)
        {
            /* Type is not restricted, check for size mismatch */
            if (dwType == REG_BINARY)
            {
                DWORD cbExpect = 0;

                if ((dwFlags & RRF_RT_DWORD) == RRF_RT_DWORD)
                    cbExpect = 4;
                else if ((dwFlags & RRF_RT_DWORD) == RRF_RT_QWORD)
                    cbExpect = 8;

                if (cbExpect && cbData != cbExpect)
                    *ret = ERROR_DATATYPE_MISMATCH;
            }
        }
        else *ret = ERROR_UNSUPPORTED_TYPE;
    }
}


/******************************************************************************
 * RegGetValueW   [ADVAPI32.@]
 *
 * Retrieves the type and data for a value name associated with a key 
 * optionally expanding it's content and restricting it's type.
 *
 * PARAMS
 *  hKey      [I] Handle to an open key.
 *  pszSubKey [I] Name of the subkey of hKey.
 *  pszValue  [I] Name of value under hKey/szSubKey to query.
 *  dwFlags   [I] Flags restricting the value type to retrieve.
 *  pdwType   [O] Destination for the values type, may be NULL.
 *  pvData    [O] Destination for the values content, may be NULL.
 *  pcbData   [I/O] Size of pvData, updated with the size required to 
 *                  retrieve the whole content.
 *
 * RETURNS
 *  Success: ERROR_SUCCESS
 *  Failure: nonzero error code from Winerror.h
 *
 * NOTES
 *  - Unless RRF_NOEXPAND is specified REG_EXPAND_SZ is automatically expanded
 *    and REG_SZ is retrieved instead.
 *  - Restrictions are applied after expanding, using RRF_RT_REG_EXPAND_SZ 
 *    without RRF_NOEXPAND is thus not allowed.
 */
LONG WINAPI
RegGetValueW( HKEY hKey, LPCWSTR pszSubKey, LPCWSTR pszValue, 
              DWORD dwFlags, LPDWORD pdwType, PVOID pvData,
              LPDWORD pcbData )
{
    DWORD dwType, cbData = pcbData ? *pcbData : 0;
    PVOID pvBuf = NULL;
    LONG ret;

    TRACE("(%p,%s,%s,%ld,%p,%p,%p=%ld)\n", 
          hKey, debugstr_w(pszSubKey), debugstr_w(pszValue), dwFlags, pdwType,
          pvData, pcbData, cbData);

    if ((dwFlags & RRF_RT_REG_EXPAND_SZ) && !(dwFlags & RRF_NOEXPAND))
        return ERROR_INVALID_PARAMETER;

    if (pszSubKey && pszSubKey[0])
    {
        ret = RegOpenKeyExW(hKey, pszSubKey, 0, KEY_QUERY_VALUE, &hKey);
        if (ret != ERROR_SUCCESS) return ret;
    }

    ret = RegQueryValueExW(hKey, pszValue, NULL, &dwType, pvData, &cbData);
    
    /* If we are going to expand we need to read in the whole the value even
     * if the passed buffer was too small as the expanded string might be
     * smaller than the unexpanded one and could fit into cbData bytes. */
    if ((ret == ERROR_SUCCESS || ret == ERROR_MORE_DATA) &&
        (dwType == REG_EXPAND_SZ && !(dwFlags & RRF_NOEXPAND)))
    {
        do {
            if (pvBuf) HeapFree(GetProcessHeap(), 0, pvBuf);
            
            pvBuf = HeapAlloc(GetProcessHeap(), 0, cbData);
            if (!pvBuf)
            {
                ret = ERROR_NOT_ENOUGH_MEMORY;
                break;
            }

            if (ret == ERROR_MORE_DATA)
                ret = RegQueryValueExW(hKey, pszValue, NULL, 
                                       &dwType, pvBuf, &cbData);
            else
            {
                /* Even if cbData was large enough we have to copy the 
                 * string since ExpandEnvironmentStrings can't handle
                 * overlapping buffers. */
                CopyMemory(pvBuf, pvData, cbData);
            }

            /* Both the type or the value itself could have been modified in
             * between so we have to keep retrying until the buffer is large
             * enough or we no longer have to expand the value. */
        } while (dwType == REG_EXPAND_SZ && ret == ERROR_MORE_DATA);

        if (ret == ERROR_SUCCESS)
        {
            if (dwType == REG_EXPAND_SZ)
            {
                cbData = ExpandEnvironmentStringsW(pvBuf, pvData,
                                                   pcbData ? *pcbData : 0);
                dwType = REG_SZ;
                if(pcbData && cbData > *pcbData)
                    ret = ERROR_MORE_DATA;
            }
            else if (pcbData)
                CopyMemory(pvData, pvBuf, *pcbData);
        }

        if (pvBuf) HeapFree(GetProcessHeap(), 0, pvBuf);
    }

    if (pszSubKey && pszSubKey[0])
        RegCloseKey(hKey);

    RegpApplyRestrictions(dwFlags, dwType, cbData, &ret);

    if (pcbData && ret != ERROR_SUCCESS && (dwFlags & RRF_ZEROONFAILURE))
        ZeroMemory(pvData, *pcbData);

    if (pdwType) *pdwType = dwType;
    if (pcbData) *pcbData = cbData;

    return ret;
}


/******************************************************************************
 * RegGetValueA   [ADVAPI32.@]
 *
 * See RegGetValueW.
 */