ControlFilterHandler.cpp

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//
//    (C) Copyright 2011 EaseFilter Technologies Inc.
//    All Rights Reserved
//
//    This software is part of a licensed software product and may
//    only be used or copied in accordance with the terms of that license.
//

#include "stdafx.h"
#include "Tools.h"
#include "FilterAPI.h"
#include "UnitTest.h"


#define PrintMessage    wprintf //ToDebugger

BOOL 
ProcessControlFilter( IN    PMESSAGE_SEND_DATA pSendMessage,IN OUT  PMESSAGE_REPLY_DATA pReplyMessage )
{
    BOOL ret = TRUE;


    try
    {
        
        switch( pSendMessage->MessageType )
        {
        
        case PRE_CREATE:
            {
                //
                //For reparse file/folder open.
                //
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {
                   PrintMessage(L"File:%ws will be redirected to new file:%ws open",pSendMessage->FileName,GetTestReparseFileName());

                   //the file name must be unicode string, file name length must be less than MAX_PATH.
                   memcpy(pReplyMessage->ReplyData.Data.DataBuffer,GetTestReparseFileName(),(ULONG)wcslen(GetTestReparseFileName())*sizeof(WCHAR));
                   pReplyMessage->ReplyData.Data.DataBufferLength =(ULONG)wcslen(GetTestReparseFileName())*sizeof(WCHAR);
                   
                   pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_COMPLETE_PRE_OPERATION|FILTER_DATA_BUFFER_IS_UPDATED;
                   pReplyMessage->ReturnStatus = STATUS_REPARSE;
                }

                break;
            }

        case PRE_QUERY_INFORMATION:
            {
                
                //
                //Return your own information without go down to the file system.
                //
                
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {
                    FILE_BASIC_INFORMATION basicInfo;

                    if( pSendMessage->InfoClass == FileBasicInformation )
                    {
                        basicInfo.ChangeTime = basicInfo.LastWriteTime 
                        = basicInfo.CreationTime = basicInfo.LastAccessTime = GetTestFileTime();

                        basicInfo.FileAttributes = FILE_ATTRIBUTE_READONLY;

                        memcpy(pReplyMessage->ReplyData.Data.DataBuffer,&basicInfo,sizeof(FILE_BASIC_INFORMATION));
                        pReplyMessage->ReplyData.Data.DataBufferLength = sizeof(FILE_BASIC_INFORMATION);

                        pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_COMPLETE_PRE_OPERATION|FILTER_DATA_BUFFER_IS_UPDATED;
                        pReplyMessage->ReturnStatus = STATUS_SUCCESS;

                         PrintMessage(L"File:%ws is test file with pre-query-information-basicInfo,return with status:%0x.",pSendMessage->FileName,pReplyMessage->FilterStatus);
                    }


                    //for other information class is the same process.
                }           

                break;

            }
            
        case POST_QUERY_INFORMATION:
            {
                
                //
                //Change the information which returns from the file system.
                //
                
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {               
                    if( pSendMessage->InfoClass == FileBasicInformation )
                    {
                        PFILE_BASIC_INFORMATION basicInfo = (PFILE_BASIC_INFORMATION)pSendMessage->DataBuffer;

                        basicInfo->ChangeTime = basicInfo->LastWriteTime = GetTestFileTime();
                        basicInfo->FileAttributes |= FILE_ATTRIBUTE_READONLY;

                        memcpy(pReplyMessage->ReplyData.Data.DataBuffer,basicInfo,sizeof(FILE_BASIC_INFORMATION));
                        pReplyMessage->ReplyData.Data.DataBufferLength = sizeof(FILE_BASIC_INFORMATION);

                        pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_DATA_BUFFER_IS_UPDATED;
                        pReplyMessage->ReturnStatus = STATUS_SUCCESS;
                    }

                    //for other information class is the same process.
                }
            

                break;
            }


        case PRE_SET_INFORMATION:
            {
                

                //
                //Change the information before write down to the file system.
                //
                
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {
                    
                    if( pSendMessage->InfoClass == FileBasicInformation )
                    {
                        PFILE_BASIC_INFORMATION basicInfo = (PFILE_BASIC_INFORMATION)pSendMessage->DataBuffer;

                        basicInfo->ChangeTime = basicInfo->LastWriteTime = GetTestFileTime();
                        basicInfo->FileAttributes = FILE_ATTRIBUTE_READONLY;

                        memcpy(pReplyMessage->ReplyData.Data.DataBuffer,basicInfo,sizeof(FILE_BASIC_INFORMATION));
                        pReplyMessage->ReplyData.Data.DataBufferLength = sizeof(FILE_BASIC_INFORMATION);

                        pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_DATA_BUFFER_IS_UPDATED;
                        pReplyMessage->ReturnStatus = STATUS_SUCCESS;

                    }

                    //for other information class is the same process.
                }

            
                break;
            }

        //For POST_SET_INFORMATION, you can't change anything, since the data was written to the file system.
       
        //
        //For PRE_DIRECTORY,you can complete it and return your own directory data,the data structure format
        //must be the same as information class from the request,you can reference POST_DIRECTORY.

        case POST_DIRECTORY:
            {
                //
                //Change the information which returns from the file system.
                //
                if(STATUS_SUCCESS == pSendMessage->Status && IsTestFolder(pSendMessage->FileName) )
                {                   


                    //here we use FileBothDirectoryInformation as example, for other classes, you can do the same operation.
                    if( pSendMessage->InfoClass == FileBothDirectoryInformation )
                    {
                        memcpy(pReplyMessage->ReplyData.Data.DataBuffer,pSendMessage->DataBuffer,pSendMessage->DataBufferLength);
                        pReplyMessage->ReplyData.Data.DataBufferLength = pSendMessage->DataBufferLength;
                        pReplyMessage->ReturnStatus = STATUS_SUCCESS;

                        PFILE_BOTH_DIR_INFORMATION      fileBothDirInfo = (PFILE_BOTH_DIR_INFORMATION)pReplyMessage->ReplyData.Data.DataBuffer;
                        ULONG   returnBufferLength = 0;
                        ULONG   totalBufferLength = pReplyMessage->ReplyData.Data.DataBufferLength;

                        if( NULL == fileBothDirInfo )
                        {
                            PrintErrorMessage(L"POST_DIRECTORY return empty databuffer",0);
                        }

                        BOOL isDatabufferUpdated = FALSE;

                        while( fileBothDirInfo )
                        {
                            ULONG nextOffset = fileBothDirInfo->NextEntryOffset;

                            PrintMessage(L"FileName:%ws Attributes:0x%0x FileSize:%I64d\n"
                                ,fileBothDirInfo->FileName,fileBothDirInfo->FileAttributes,fileBothDirInfo->EndOfFile.QuadPart);

                            //You can modify the data of the fileBothDirInfo, but must be careful to change the size of the entry.
                            //This structure must be aligned on a LONGLONG (8-byte) boundary. If a buffer contains two or more of these structures, 
                            //the NextEntryOffset value in each entry, except the last, falls on an 8-byte boundary. 

                            //Test: Hide all the files whose file size greater than 1024 bytes.
                            if( fileBothDirInfo->EndOfFile.QuadPart > 1024 )
                            {               
                                if( nextOffset != 0 )
                                {
                                    PrintMessage(L"File %ws is filtered",fileBothDirInfo->FileName);
                                    memmove (fileBothDirInfo,(PUCHAR)fileBothDirInfo + nextOffset,totalBufferLength - returnBufferLength - nextOffset );
                                    isDatabufferUpdated = TRUE;
                                    continue;
                                }
                                else
                                {
                                    fileBothDirInfo->NextEntryOffset = 0;
                                }
                            }

                            //Test: Add ReadOnly to the FileAttributes, change FileSize to test file size for all files;
                            if(NULL == (fileBothDirInfo->FileAttributes & FILE_ATTRIBUTE_DIRECTORY) )
                            {
                                PrintMessage(L"File %ws attributs:0x%0x was added ReadOnly,Filesize:%I64d was changed to 1234567890"
                                    ,fileBothDirInfo->FileName,fileBothDirInfo->FileAttributes,fileBothDirInfo->EndOfFile.QuadPart);

                                fileBothDirInfo->FileAttributes |= FILE_ATTRIBUTE_READONLY;
                                fileBothDirInfo->EndOfFile.QuadPart = GetTestFileSize();
                                isDatabufferUpdated = TRUE;
                            }

                            returnBufferLength += nextOffset;
                            
                            if( nextOffset == 0)
                            {
                                returnBufferLength += sizeof(FILE_BOTH_DIR_INFORMATION) + fileBothDirInfo->FileNameLength - sizeof(WCHAR);
                                fileBothDirInfo = NULL;
                            }
                            else
                            {
                                fileBothDirInfo = (PFILE_BOTH_DIR_INFORMATION)((PUCHAR)fileBothDirInfo + nextOffset);
                            }

                        }

                        pReplyMessage->ReplyData.Data.DataBufferLength = returnBufferLength;

                        //if you filter out all the files, you can return no more files status. The system won't generate another request.
                        if( returnBufferLength == 0 )
                        {
                            pReplyMessage->ReturnStatus = STATUS_NO_MORE_FILES; 
                        }

                        if( isDatabufferUpdated )
                        {
                            PrintMessage(L"Update directory buffer,original length:%d new length:%d",pSendMessage->DataBufferLength,pReplyMessage->ReplyData.Data.DataBufferLength);
                            pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_DATA_BUFFER_IS_UPDATED;
                        }
                    }
                }

                break;
            }

            case PRE_FASTIO_READ:
            case PRE_CACHE_READ:
            case PRE_NOCACHE_READ:
            case PRE_PAGING_IO_READ:
            {
                //
                //Return your own data without go down to the file system.
                //
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {
                    ULONG dataLength = (ULONG)strlen(GetReplaceData());

                    if( pSendMessage->Length < dataLength )
                    {
                        dataLength = pSendMessage->Length;
                    }

                    memcpy(pReplyMessage->ReplyData.Data.DataBuffer,GetReplaceData(),dataLength);
                    pReplyMessage->ReplyData.Data.DataBufferLength = dataLength;

                    pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_COMPLETE_PRE_OPERATION|FILTER_DATA_BUFFER_IS_UPDATED;
                    pReplyMessage->ReturnStatus = STATUS_SUCCESS;
                }

               break;
            }

            case POST_FASTIO_READ:
            case POST_CACHE_READ: 
            case POST_NOCACHE_READ:
            case POST_PAGING_IO_READ:
            {
                //
                //Modify the data which returns from the file system.
                //
                
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {
                    
                    memcpy(pReplyMessage->ReplyData.Data.DataBuffer,pSendMessage->DataBuffer,pSendMessage->DataBufferLength);
                    //merge test data to the beginning of the buffer.
                    ULONG dataLength = (ULONG)strlen(GetReplaceData());

                    if( pSendMessage->Length < dataLength )
                    {
                        dataLength = pSendMessage->Length;
                    }

                    memcpy(pReplyMessage->ReplyData.Data.DataBuffer,GetReplaceData(),dataLength);
                    pReplyMessage->ReplyData.Data.DataBufferLength = dataLength;

                                    
                    pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_DATA_BUFFER_IS_UPDATED;
                    pReplyMessage->ReturnStatus = STATUS_SUCCESS;
                }


               break;
            }


            case PRE_FASTIO_WRITE:
            case PRE_CACHE_WRITE:
            case PRE_NOCACHE_WRITE:
            case PRE_PAGING_IO_WRITE:
            {
                //
                //Modiy the write data buffer before it goes down to the file system.
                //
                
                if( IsTestFile(pSendMessage->FileName,pSendMessage->FileNameLength) )
                {
                    memcpy(pReplyMessage->ReplyData.Data.DataBuffer,pSendMessage->DataBuffer,pSendMessage->DataBufferLength);
                    //merge test data to the beginning of the buffer.
                    ULONG dataLength = (ULONG)strlen(GetReplaceData());

                    if( pSendMessage->Length < dataLength )
                    {
                        dataLength = pSendMessage->Length;
                    }

                    memcpy(pReplyMessage->ReplyData.Data.DataBuffer,GetReplaceData(),dataLength);
                    pReplyMessage->ReplyData.Data.DataBufferLength = dataLength;


                    pReplyMessage->FilterStatus = FILTER_MESSAGE_IS_DIRTY|FILTER_DATA_BUFFER_IS_UPDATED;
                    pReplyMessage->ReturnStatus = STATUS_SUCCESS;
                }

               break;
            }

            //For post write operation, the data was written to the file system,at this point, we can't change anything.

            default: break;
        
        }
    }
    catch(...)
    {
        PrintErrorMessage( L"ProcessControlFilter exception.",GetLastError());     
        ret = FALSE;
    }

    return ret;
}