/*

    File:       SimpleDataQueueTool.c

    Description:    This file shows how to setup a shared memory region with a KEXT which allows

                        a user space application to dequeue items that were placed into an IODataQueue.

    Author:     MK

    Copyright:  © Copyright 2001 Apple Computer, Inc. All rights reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

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                        are granted by Apple herein, including but not limited to any patent rights that

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                        Software may be incorporated.

                        The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO

                        WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

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                        PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN

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    Change History (most recent first):

                    1.0d1

*/

#include <IOKit/IOKitLib.h>

#include <IOKit/IODataQueueShared.h>

#include <IOKit/IODataQueueClient.h>

#include <ApplicationServices/ApplicationServices.h>

#include <pthread.h>

#include <stdio.h>

#include <stdlib.h>

#include "SharedData.h"

#define kMyDriversIOKitClassName    "com_apple_dts_SimpleDataQueue"

#define kMyPathToSystemLog      "/var/log/system.log"

static IOReturn

MyListenForData(io_connect_t connection)

{

    kern_return_t       kernResult; 

    UInt8           data;

    UInt32          dataSize = sizeof(UInt8);

    IODataQueueMemory *     queueMappedMemory;

    vm_size_t           queueMappedMemorySize;

    vm_address_t        address = nil;

    vm_size_t           size = 0;

    unsigned int        msgType = 1;

    mach_port_t         recvPort;

    // Allocates and returns a new mach port able to receive data available notifications from an IODataQueue.

    recvPort = IODataQueueAllocateNotificationPort();

    if (!recvPort)

    {

        printf("IODataQueueAllocateNotificationPort returned a NULL mach_port_t\n");

        return kIOReturnError;

    }

    // IOConnectSetNotificationPort will call registerNotificationPort() inside your user client class.

    kernResult = IOConnectSetNotificationPort(connection, msgType, recvPort, 0);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOConnectSetNotificationPort returned %d\n", kernResult);

        mach_port_destroy(mach_task_self(), recvPort);

        return kernResult;

    }

    // IOConnectMapMemory will call clientMemoryForType() inside your user client class.

    kernResult = IOConnectMapMemory(connection, kIODefaultMemoryType, mach_task_self(), &address, &size, kIOMapAnywhere);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOConnectMapMemory returned %d\n", kernResult );

        mach_port_destroy(mach_task_self(), recvPort);

        return kernResult;

    }

    queueMappedMemory = (IODataQueueMemory *) address;

    queueMappedMemorySize = size;    

    // IODataQueueWaitForAvailableData doesn't return until there's data on the recvPort.

    while (IODataQueueWaitForAvailableData(queueMappedMemory, recvPort) == kIOReturnSuccess)

    {            

        // IODataQueueDataAvailable returns true when the shared memory contains data to dequeue.

        while (IODataQueueDataAvailable(queueMappedMemory))

        {   

            // Dequeues the next available entry on the queue and copies it into the given data pointer.             

            kernResult = IODataQueueDequeue(queueMappedMemory, &data, &dataSize);

            if (kernResult == kIOReturnSuccess)

            {

                // The KEXT is telling us to stop listening, so exit.

                if (data == kMyStopListeningMessage) goto exit;

                printf("Data = %d, Size = %ld, Result = %d\n", data, dataSize, kernResult);

                fflush(stdout);

            }

            else

            {

                printf("IODataQueueDequeue returned %d\n", kernResult );

            }

        }

    }

exit:

    // IOConnectUnmapMemory will call clientMemoryForType() inside your user client class.

    kernResult = IOConnectUnmapMemory(connection, kIODefaultMemoryType, mach_task_self(), address);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOConnectUnmapMemory returned %d\n", kernResult);

    }

    mach_port_destroy(mach_task_self(), recvPort);

    return kernResult;

}

static void

MyLaunchConsoleApp()

{

    CFURLRef pathRef;

    pathRef = CFURLCreateWithString(NULL, CFSTR(kMyPathToSystemLog), NULL);

    if (pathRef)

    {

        LSOpenCFURLRef(pathRef, NULL);

        CFRelease(pathRef);

    }

}

int

main(int argc, char* argv[])

{

    kern_return_t   kernResult; 

    mach_port_t     masterPort;

    io_iterator_t   iterator;

    io_service_t    serviceObject;

    CFDictionaryRef classToMatch;

    pthread_t       dataQueueThread;

    io_connect_t    connection;

    int         err;

    // This will launch the Console.app so you can see the IOLogs from the KEXT.

    MyLaunchConsoleApp();

    // Returns the mach port used to initiate communication with IOKit.

    kernResult = IOMasterPort(MACH_PORT_NULL, &masterPort);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOMasterPort returned %d\n", kernResult);

        return 0;

    }

    classToMatch = IOServiceMatching(kMyDriversIOKitClassName);

    if (classToMatch == NULL)

    {

        printf("IOServiceMatching returned a NULL dictionary.\n");

        return 0;

    }

    // This creates an io_iterator_t of all instances of our drivers class that exist in the IORegistry.

    kernResult = IOServiceGetMatchingServices(masterPort, classToMatch, &iterator);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOServiceGetMatchingServices returned %d\n", kernResult);

        return 0;

    }

    // Get the first item in the iterator.

    serviceObject = IOIteratorNext(iterator);

    // Release the io_iterator_t now that we're done with it.

    IOObjectRelease(iterator);

    if (!serviceObject)

    {

        printf("Couldn't find any matches.\n");

        return 0;

    }

    // This call will cause the user client to be instantiated.

    kernResult = IOServiceOpen(serviceObject, mach_task_self(), 0, &connection);

    IOObjectRelease(serviceObject);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOServiceOpen returned %d\n", kernResult);

        return 0;

    }

    // This moves the IODataQueue listener to a separate thread.

    err = pthread_create(&dataQueueThread, NULL, (void *)MyListenForData, (void *)connection);

    if (err != noErr)

    {

        printf( "pthread_create returned %d\n", err);

        goto close;

    }

    /*****This is where you would do other things while waiting for kernel events.*****/

    // This waits for the listener thread to exit.

    pthread_join(dataQueueThread, (void **)&kernResult);

close:

    // Close a connection to an IOService and destroy the connect handle.

    kernResult = IOServiceClose(connection);

    if (kernResult != kIOReturnSuccess)

    {

        printf("IOServiceClose returned %d\n", kernResult);

    }

    return 0;

}