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📄 dirctrl.c

📁 winddk src目录下的文件系统驱动源码压缩!
💻 C
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                    //
                    //  Now we have an entry to return to our caller.  We'll convert
                    //  the name from the form in the dirent to a <name>.<ext> form.
                    //  We'll case on the type of information requested and fill up
                    //  the user buffer if everything fits.
                    //

                    Fat8dot3ToString( IrpContext, Dirent, TRUE, &Fat8Dot3String );
    
                    //
                    //  Determine the UNICODE length of the file name.
                    //
    
                    FileNameLength = RtlOemStringToCountedUnicodeSize(&Fat8Dot3String);

                    //
                    //  Here are the rules concerning filling up the buffer:
                    //
                    //  1.  The Io system garentees that there will always be
                    //      enough room for at least one base record.
                    //
                    //  2.  If the full first record (including file name) cannot
                    //      fit, as much of the name as possible is copied and
                    //      STATUS_BUFFER_OVERFLOW is returned.
                    //
                    //  3.  If a subsequent record cannot completely fit into the
                    //      buffer, none of it (as in 0 bytes) is copied, and
                    //      STATUS_SUCCESS is returned.  A subsequent query will
                    //      pick up with this record.
                    //
    
                    BytesRemainingInBuffer = UserBufferLength - NextEntry;
    
                    if ( (NextEntry != 0) &&
                         ( (BaseLength + FileNameLength > BytesRemainingInBuffer) ||
                           (UserBufferLength < NextEntry) ) ) {
    
                        DebugTrace(0, Dbg, "Next entry won't fit\n", 0);
    
                        try_return( Status = STATUS_SUCCESS );
                    }
    
                    ASSERT( BytesRemainingInBuffer >= BaseLength );

                    //
                    //  Zero the base part of the structure.
                    //

                    RtlZeroMemory( &Buffer[NextEntry], BaseLength );

                    switch ( FileInformationClass ) {
    
                    //
                    //  Now fill the base parts of the strucure that are applicable.
                    //
    
                    case FileBothDirectoryInformation:
                    case FileFullDirectoryInformation:
                    case FileIdBothDirectoryInformation:
                    case FileIdFullDirectoryInformation:

                        DebugTrace(0, Dbg, "FatQueryDirectory -> Getting file full directory information\n", 0);
    
                        //
                        //  Get the Ea file length.
                        //
    
                        FullDirInfo = (PFILE_FULL_DIR_INFORMATION)&Buffer[NextEntry];
    
                        //
                        //  If the EAs are corrupt, ignore the error.  We don't want
                        //  to abort the directory query.
                        //
    
                        try {
    
                            FatGetEaLength( IrpContext,
                                            Vcb,
                                            Dirent,
                                            &FullDirInfo->EaSize );
    
                        } except(EXCEPTION_EXECUTE_HANDLER) {
    
                              FatResetExceptionState( IrpContext );
                              FullDirInfo->EaSize = 0;
                        }
                        
                    case FileDirectoryInformation:
    
                        DirInfo = (PFILE_DIRECTORY_INFORMATION)&Buffer[NextEntry];
    
                        FatGetDirTimes( IrpContext, Dirent, DirInfo );
    
                        DirInfo->EndOfFile.QuadPart = Dirent->FileSize;
    
                        if (!FlagOn( Dirent->Attributes, FAT_DIRENT_ATTR_DIRECTORY )) {
    
                            DirInfo->AllocationSize.QuadPart =
                               (((Dirent->FileSize + DiskAllocSize - 1) / DiskAllocSize) *
                                DiskAllocSize );
                        }
    
                        DirInfo->FileAttributes = Dirent->Attributes != 0 ?
                                                  Dirent->Attributes :
                                                  FILE_ATTRIBUTE_NORMAL;
    
                        DirInfo->FileIndex = NextVbo;
    
                        DirInfo->FileNameLength = FileNameLength;
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Name = \"%Z\"\n", &Fat8Dot3String);
    
                        break;
    
                    case FileNamesInformation:
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Getting file names information\n", 0);
    
                        NamesInfo = (PFILE_NAMES_INFORMATION)&Buffer[NextEntry];
    
                        NamesInfo->FileIndex = NextVbo;
    
                        NamesInfo->FileNameLength = FileNameLength;
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Name = \"%Z\"\n", &Fat8Dot3String );
    
                        break;
    
                    default:
    
                        FatBugCheck( FileInformationClass, 0, 0 );
                    }

                    BytesConverted = 0;
    
                    Status = RtlOemToUnicodeN( (PWCH)&Buffer[NextEntry + BaseLength],
                                               BytesRemainingInBuffer - BaseLength,
                                               &BytesConverted,
                                               Fat8Dot3String.Buffer,
                                               Fat8Dot3String.Length );
                    
                    //
                    //  Check for the case that a single entry doesn't fit.
                    //  This should only get this far on the first entry
                    //
    
                    if (BytesConverted < FileNameLength) {
    
                        ASSERT( NextEntry == 0 );
                        Status = STATUS_BUFFER_OVERFLOW;
                    }
    
                    //
                    //  Set up the previous next entry offset
                    //
    
                    *((PULONG)(&Buffer[LastEntry])) = NextEntry - LastEntry;
    
                    //
                    //  And indicate how much of the user buffer we have currently
                    //  used up.  We must compute this value before we long align
                    //  ourselves for the next entry
                    //
    
                    Irp->IoStatus.Information = QuadAlign( Irp->IoStatus.Information ) +
                                                BaseLength + BytesConverted;
    
                    //
                    //  If something happened with the conversion, bail here.
                    //
    
                    if ( !NT_SUCCESS( Status ) ) {
    
                        try_return( NOTHING );
                    }

                } else {

                    ULONG ShortNameLength;
    
                    FileNameLength = LongFileName.Length;
    
                    //
                    //  Here are the rules concerning filling up the buffer:
                    //
                    //  1.  The Io system garentees that there will always be
                    //      enough room for at least one base record.
                    //
                    //  2.  If the full first record (including file name) cannot
                    //      fit, as much of the name as possible is copied and
                    //      STATUS_BUFFER_OVERFLOW is returned.
                    //
                    //  3.  If a subsequent record cannot completely fit into the
                    //      buffer, none of it (as in 0 bytes) is copied, and
                    //      STATUS_SUCCESS is returned.  A subsequent query will
                    //      pick up with this record.
                    //
    
                    BytesRemainingInBuffer = UserBufferLength - NextEntry;
    
                    if ( (NextEntry != 0) &&
                         ( (BaseLength + FileNameLength > BytesRemainingInBuffer) ||
                           (UserBufferLength < NextEntry) ) ) {
    
                        DebugTrace(0, Dbg, "Next entry won't fit\n", 0);
    
                        try_return( Status = STATUS_SUCCESS );
                    }
    
                    ASSERT( BytesRemainingInBuffer >= BaseLength );
    
                    //
                    //  Zero the base part of the structure.
                    //

                    RtlZeroMemory( &Buffer[NextEntry], BaseLength );

                    switch ( FileInformationClass ) {
    
                    //
                    //  Now fill the base parts of the strucure that are applicable.
                    //
    
                    case FileBothDirectoryInformation:
                    case FileIdBothDirectoryInformation:
    
                        BothDirInfo = (PFILE_BOTH_DIR_INFORMATION)&Buffer[NextEntry];
    
                        //
                        //  Now we have an entry to return to our caller.  We'll convert
                        //  the name from the form in the dirent to a <name>.<ext> form.
                        //  We'll case on the type of information requested and fill up
                        //  the user buffer if everything fits.
                        //
    
                        Fat8dot3ToString( IrpContext, Dirent, FALSE, &Fat8Dot3String );
    
                        ASSERT( Fat8Dot3String.Length <= 12 );
    
                        Status = RtlOemToUnicodeN( &BothDirInfo->ShortName[0],
                                                   12*sizeof(WCHAR),
                                                   &ShortNameLength,
                                                   Fat8Dot3String.Buffer,
                                                   Fat8Dot3String.Length );
    
                        ASSERT( Status != STATUS_BUFFER_OVERFLOW );
                        ASSERT( ShortNameLength <= 12*sizeof(WCHAR) );
    
                        //
                        //  Copy the length into the dirinfo structure.  Note
                        //  that the LHS below is a USHORT, so it can not
                        //  be specificed as the OUT parameter above.
                        //
    
                        BothDirInfo->ShortNameLength = (UCHAR)ShortNameLength;
    
                        //
                        //  If something happened with the conversion, bail here.
                        //
    
                        if ( !NT_SUCCESS( Status ) ) {
    
                            try_return( NOTHING );
                        }
    
                    case FileFullDirectoryInformation:
                    case FileIdFullDirectoryInformation:
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Getting file full directory information\n", 0);
    
                        //
                        //  Get the Ea file length.
                        //
    
                        FullDirInfo = (PFILE_FULL_DIR_INFORMATION)&Buffer[NextEntry];
    
                        //
                        //  If the EAs are corrupt, ignore the error.  We don't want
                        //  to abort the directory query.
                        //
    
                        try {
    
                            FatGetEaLength( IrpContext,
                                            Vcb,
                                            Dirent,
                                            &FullDirInfo->EaSize );
    
                        } except(EXCEPTION_EXECUTE_HANDLER) {
    
                              FatResetExceptionState( IrpContext );
                              FullDirInfo->EaSize = 0;
                        }
    
                    case FileDirectoryInformation:
    
                        DirInfo = (PFILE_DIRECTORY_INFORMATION)&Buffer[NextEntry];
    
                        FatGetDirTimes( IrpContext, Dirent, DirInfo );
    
                        DirInfo->EndOfFile.QuadPart = Dirent->FileSize;
    
                        if (!FlagOn( Dirent->Attributes, FAT_DIRENT_ATTR_DIRECTORY )) {
    
                            DirInfo->AllocationSize.QuadPart = (
                                                            (( Dirent->FileSize
                                                               + DiskAllocSize - 1 )
                                                             / DiskAllocSize )
                                                            * DiskAllocSize );
                        }
    
                        DirInfo->FileAttributes = Dirent->Attributes != 0 ?
                                                  Dirent->Attributes :
                                                  FILE_ATTRIBUTE_NORMAL;
    
                        DirInfo->FileIndex = NextVbo;
    
                        DirInfo->FileNameLength = FileNameLength;
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Name = \"%Z\"\n", &Fat8Dot3String);
    
                        break;
    
                    case FileNamesInformation:
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Getting file names information\n", 0);
    
                        NamesInfo = (PFILE_NAMES_INFORMATION)&Buffer[NextEntry];
    
                        NamesInfo->FileIndex = NextVbo;
    
                        NamesInfo->FileNameLength = FileNameLength;
    
                        DebugTrace(0, Dbg, "FatQueryDirectory -> Name = \"%Z\"\n", &Fat8Dot3String );
    
                        break;
    
                    default:
    
                        FatBugCheck( FileInformationClass, 0, 0 );
                    }

                    BytesConverted = BytesRemainingInBuffer - BaseLength >= FileNameLength ?
                                     FileNameLength :
                                     BytesRemainingInBuffer - BaseLength;
    
                    RtlCopyMemory( &Buffer[NextEntry + BaseLength],
                                   &LongFileName.Buffer[0],
                                   BytesConverted );
    
                    //
                    //  Set up the previous next entry offset
                    //
    
                    *((PULONG)(&Buffer[LastEntry])) = NextEntry - LastEntry;

                    //
                    //  And indicate how much of the user buffer we have currently
                    //  used up.  We must compute this value before we long align
                    //  ourselves for the next entry
                    //
    
                    Irp->IoStatus.Information = QuadAlign( Irp->IoStatus.Information ) +
                                                BaseLength + BytesConverted;

                    //
                    //  Check for the case that a single entry doesn't fit.
                    //  This should only get this far on the first entry.
                    //

                    if (BytesConverted < FileNameLength) {

                        ASSERT( NextEntry == 0 );

                        try_return( Status = STATUS_BUFFER_OVERFLOW );
                    }
                }

                //

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