#include "stddef.h"
#include "string.h"
#include "ntddk.h"
#include "ntddstor.h"
#include "cdrom.h"
#include "ioctl.h"
#include "scratch.h"
Include dependency graph for aacs.c:
Functions
	_IRQL_requires_max_ (APC_LEVEL)
Function Documentation

◆ _IRQL_requires_max_()

_IRQL_requires_max_ ( APC_LEVEL )
Definition at line 54 of file aacs.c.
{
    NTSTATUS            status = STATUS_SUCCESS;
    PAACS_LAYER_NUMBER  layerNumber = NULL;
    PVOID               outputBuffer = NULL;
    ULONG               transferSize = sizeof(READ_DVD_STRUCTURES_HEADER);
 
    PAGED_CODE();
 
    *DataLength = 0;
 
    status = WdfRequestRetrieveInputBuffer(Request,
                                           RequestParameters.Parameters.DeviceIoControl.InputBufferLength,
                                           (PVOID*)&layerNumber,
                                           NULL);
 
    if (NT_SUCCESS(status))
    {
        status = WdfRequestRetrieveOutputBuffer(Request,
                                                RequestParameters.Parameters.DeviceIoControl.OutputBufferLength,
                                                (PVOID*)&outputBuffer,
                                                NULL);
    }
 
    if (NT_SUCCESS(status))
    {
        if (RequestParameters.Parameters.DeviceIoControl.IoControlCode == IOCTL_AACS_READ_MEDIA_KEY_BLOCK)
        {
            // maximum size for this transfer is one pack + header
            transferSize += AACS_MKB_PACK_SIZE;
        }
 
        if (transferSize > DeviceExtension->ScratchContext.ScratchBufferSize)
        {
            // rare case. normally the size of scratch buffer is 64k.
            status = STATUS_INTERNAL_ERROR;
        }
    }
 
    if (NT_SUCCESS(status))
    {
        UCHAR                       rmdBlockNumber = 0;
        BOOLEAN                     sendChangedCommand = TRUE;
        BOOLEAN                     shouldRetry = TRUE;
        CDB                         cdb;
 
        ScratchBuffer_BeginUse(DeviceExtension);
 
        RtlZeroMemory(&cdb, sizeof(CDB));
        // Set up the CDB
        cdb.READ_DVD_STRUCTURE.OperationCode = SCSIOP_READ_DVD_STRUCTURE;
        // cdb->AsByte[1] = 0x01; // AACS sub-command not required for this
 
        cdb.READ_DVD_STRUCTURE.LayerNumber = (UCHAR)(*layerNumber);
        cdb.READ_DVD_STRUCTURE.Format = 0x83; // MKB
        cdb.READ_DVD_STRUCTURE.AllocationLength[0] = (UCHAR)(transferSize >> (8*1));
        cdb.READ_DVD_STRUCTURE.AllocationLength[1] = (UCHAR)(transferSize >> (8*0));
 
        while (sendChangedCommand)
        {
            // RMDBlockNumber is set to zero....
            // RMDBlockNumber[3] maybe changed for other blocks.
            cdb.READ_DVD_STRUCTURE.RMDBlockNumber[3] = rmdBlockNumber;
 
            if (shouldRetry)
            {
                status = ScratchBuffer_ExecuteCdb(DeviceExtension, Request, transferSize, TRUE, &cdb, 12);
            }
 
    #ifdef ENABLE_AACS_TESTING
            if (RequestParameters.Parameters.DeviceIoControl.IoControlCode == IOCTL_AACS_READ_MEDIA_KEY_BLOCK_SIZE)
            {
                static const UCHAR results[] = { 0x80, 0x02, 0x00, 0x02 };
                RtlCopyMemory(DeviceExtension->ScratchContext.ScratchBuffer, results, SIZEOF_ARRAY(results));
                status = STATUS_SUCCESS;
            }
            else if (RequestParameters.Parameters.DeviceIoControl.IoControlCode == IOCTL_AACS_READ_MEDIA_KEY_BLOCK)
            {
                static const UCHAR results[] = { 0x80, 0x02, 0x00, 0x02 };
                static const UCHAR defaultFill = 0x30; // '0'
                RtlFillMemory(DeviceExtension->ScratchContext.ScratchBuffer, 0x8004, defaultFill);
                RtlCopyMemory(DeviceExtension->ScratchContext.ScratchBuffer, results, SIZEOF_ARRAY(results));
                status = STATUS_SUCCESS;
            }
    #endif //ENABLE_AACS_TESTING
 
            if (NT_SUCCESS(status))
            {
                // command succeeded, process data...
                PDVD_DESCRIPTOR_HEADER  header = DeviceExtension->ScratchContext.ScratchBuffer;
                UCHAR                   thisPackNumber = cdb.READ_DVD_STRUCTURE.RMDBlockNumber[3];
                UCHAR                   otherPacks = header->Reserved[1];
 
                // validate and zero-base the otherPacks
                if (otherPacks == 0)
                {
                    TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
                                "AACS: Device is reporting zero total packs (invalid)\n"));
                    *DataLength = 0;
                    status = STATUS_IO_DEVICE_ERROR;
                }
                else
                {
                    otherPacks--;
 
                    if (RequestParameters.Parameters.DeviceIoControl.IoControlCode == IOCTL_AACS_READ_MEDIA_KEY_BLOCK_SIZE)
                    {
                        // if not already requested last pack, do so now
                        if (otherPacks != thisPackNumber)
                        {
                            // re-send the command for the other pack number.
                            // this is safe here because NT_SUCCESS() is TRUE,
                            // and all the rest of this routine does is SetHardError()
                            // and release of resources we're still about to use.
 
                            // re-zero the output buffer
                            RtlZeroMemory(DeviceExtension->ScratchContext.ScratchBuffer, sizeof(READ_DVD_STRUCTURES_HEADER));
 
                            // modify the CDB to get the very last pack of the MKB
                            rmdBlockNumber = otherPacks;
 
                            transferSize = sizeof(READ_DVD_STRUCTURES_HEADER);
 
                            // keep items clean
                            ScratchBuffer_ResetItems(DeviceExtension, TRUE);
 
                            // make sure the loop will be executed for modified command.
                            sendChangedCommand = TRUE;
                            shouldRetry = TRUE;
                        }
                        else
                        {
                            // this request already got the last pack
                            // so just interpret the data
                            REVERSE_SHORT(&header->Length);
                            if (header->Length < sizeof(DVD_DESCRIPTOR_HEADER) - RTL_SIZEOF_THROUGH_FIELD(DVD_DESCRIPTOR_HEADER, Length))
                            {
                                *DataLength = 0;
                                status = STATUS_IO_DEVICE_ERROR;
                            }
                            else
                            {
                                ULONG totalSize = header->Length;
                                // subtract out any remaining bytes in the header
                                // to get the number of usable bytes in this pack
                                totalSize -= sizeof(DVD_DESCRIPTOR_HEADER) - RTL_SIZEOF_THROUGH_FIELD(DVD_DESCRIPTOR_HEADER, Length);
                                totalSize += otherPacks * AACS_MKB_PACK_SIZE;
 
                                // save the result and complete the request
                                *((PULONG)outputBuffer) = totalSize;
                                *DataLength = sizeof(ULONG);
                                status = STATUS_SUCCESS;
                            }
                            // This will exit the loop of sendChangedCommand
                            sendChangedCommand = FALSE;
                            shouldRetry = FALSE;
                        }
                    }
                    else if (RequestParameters.Parameters.DeviceIoControl.IoControlCode == IOCTL_AACS_READ_MEDIA_KEY_BLOCK)
                    {
                        // make length field native byte ordering
                        REVERSE_SHORT(&header->Length);
 
                        // exit if getting invalid data from the drive
                        if (header->Length < sizeof(DVD_DESCRIPTOR_HEADER) - RTL_SIZEOF_THROUGH_FIELD(DVD_DESCRIPTOR_HEADER, Length))
                        {
                            *DataLength = 0;
                            status = STATUS_IO_DEVICE_ERROR;
                        }
                        else
                        {
                            // success, how many bytes to copy for this pack?
                            ULONG totalSize = header->Length;
                            size_t originalBufferSize;
 
                            // subtract out any remaining bytes in the header
                            // to get the number of usable bytes in this pack
                            totalSize -= sizeof(DVD_DESCRIPTOR_HEADER) - RTL_SIZEOF_THROUGH_FIELD(DVD_DESCRIPTOR_HEADER, Length);
 
                            // if not the final pack, this should be a full transfer per spec
                            NT_ASSERT( (totalSize == AACS_MKB_PACK_SIZE) || (thisPackNumber == otherPacks) );
 
                            // validate the user's buffer is large enough to accept the full data
                            originalBufferSize = RequestParameters.Parameters.DeviceIoControl.OutputBufferLength;
 
                            if (originalBufferSize < (totalSize + (AACS_MKB_PACK_SIZE*thisPackNumber)))
                            {
                                // just return a slightly bigger-than-normal size
                                *DataLength = (otherPacks + 1)*AACS_MKB_PACK_SIZE;
                                status = STATUS_BUFFER_TOO_SMALL;
                            }
                            else
                            {
                                PUCHAR whereToCopy;
                                // determine where to copy to the user's memory
                                whereToCopy = outputBuffer;
                                whereToCopy += AACS_MKB_PACK_SIZE * thisPackNumber;
 
                                RtlCopyMemory(whereToCopy, header->Data, totalSize);
 
                                // update the Information field here because we already
                                // have calculated the size of the block
                                *DataLength = totalSize + (AACS_MKB_PACK_SIZE * thisPackNumber);
                                status = STATUS_SUCCESS;
 
                                // if there are more packs to get from the device, send it again....
                                if (thisPackNumber != otherPacks)
                                {
                                    // re-send the command for the next pack number.
                                    // this is safe here because NT_SUCCESS() is TRUE,
                                    // and all the rest of this routine does is SetHardError()
                                    // and release of resources we're still about to use.
 
                                    // re-zero the output buffer
                                    RtlZeroMemory(DeviceExtension->ScratchContext.ScratchBuffer, sizeof(READ_DVD_STRUCTURES_HEADER));
 
                                    // modify the CDB to get the next pack of the MKB
                                    rmdBlockNumber = cdb.READ_DVD_STRUCTURE.RMDBlockNumber[3]++;
 
                                    // modify the SRB to be resent
                                    //
                                    transferSize = AACS_MKB_PACK_SIZE + sizeof(READ_DVD_STRUCTURES_HEADER);
 
                                    // keep items clean
                                    ScratchBuffer_ResetItems(DeviceExtension, FALSE);
 
                                    // make sure the loop will be executed for modified command.
                                    sendChangedCommand = TRUE;
                                    shouldRetry = TRUE;
                                }
                                else
                                {
                                    // else, that was the end of the transfer, so just complete the request
                                    sendChangedCommand = FALSE;
                                }
                            }
                        }
 
                    } // end of IOCTL_AACS_READ_MEDIA_KEY_BLOCK
                }
            } // end of NT_SUCCESS(status)
 
            if (!NT_SUCCESS(status))
            {
                // command failed.
                sendChangedCommand = FALSE;
            }
        } //end of while (sendChangedCommand)
 
        ScratchBuffer_EndUse(DeviceExtension);
    }
 
    return status;
}
Functions

Function Documentation

◆ _IRQL_requires_max_()
