test.c

LINUX 下的字符设备

#ifndef __KERNEL__
    #define __KERNEL__
#endif
#ifndef MODULE
    #define MODULE
#endif

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>       /* printk() */
#include <linux/init.h>

//#include <linux/in.h>
#include <linux/netdevice.h>   /* struct device, and other headers */
#include <linux/etherdevice.h> /* eth_type_trans */
//#include <linux/ip.h>          /* struct iphdr */
//#include <linux/tcp.h>         /* struct tcphdr */

static int test_init(struct net_device *dev);
static int test_open(struct net_device *dev);
static int test_release(struct net_device *dev); 
static int test_config(struct net_device *dev, struct ifmap *map);
static int test_tx(struct sk_buff *skb, struct net_device *dev);
int  test_init_module(void);
void test_cleanup(void);


#define DEVICE_NAME "test"               /* name for messaging */

module_init(test_init_module);
module_exit(test_cleanup);

/********************************************************************************************************/


static struct net_device net_test =
{
    name: "eth0",
    init: test_init,
};

        static int test_init(struct net_device *dev)
{
    ether_setup(dev); /* assign some of the fields */

    dev->open            = test_open;
    dev->stop            = test_release;
    dev->set_config      = test_config;
    dev->hard_start_xmit = test_tx;
    dev->flags           &= ~(IFF_BROADCAST | IFF_LOOPBACK | IFF_MULTICAST);
    //dev->get_stats       = test_stats;
    //dev->tx_timeout     = test_tx_timeout;
    //dev->watchdog_timeo = timeout;
    //dev->do_ioctl        = test_ioctl;

    SET_MODULE_OWNER(dev);

    //dev->priv = kmalloc(sizeof(struct test_priv), GFP_KERNEL);
    return 0;
}

        static int test_config(struct net_device *dev, struct ifmap *map)
{
    return 0;
}

        static int test_tx(struct sk_buff *skb, struct net_device *dev)
{
    return 0;
}

                
        static int  test_open(struct net_device *dev)
{
    MOD_INC_USE_COUNT;
    netif_start_queue(dev);

    return 0;          /* success */
} 

        static int  test_release(struct net_device *dev) 
{
    netif_stop_queue(dev);
    MOD_DEC_USE_COUNT;
    return(0); 
} 

        int  test_init_module(void)
{
    int  result;

    result = register_netdev(&net_test); 
    if (result < 0)
    {
        printk(KERN_ERR DEVICE_NAME ": error %i registering device \"%s\"\n",
               result, net_test.name);
        return(result); 
    } 

    printk(KERN_ERR DEVICE_NAME ": init OK\n");
    return(0); 
}

        void test_cleanup(void)
{
    unregister_netdev(&net_test);
}

/*********************************************************************************************************
**                            End Of File
********************************************************************************************************/