自定义协议族

#include <linux/module.h>
#include <linux/init.h>
#include <linux/net.h>
#include <net/sock.h>

#define PF_MYFAMILY    28

static void stream_csk_destroy_sock(struct sock * sk)
{
        skb_queue_purge(&sk->sk_receive_queue);
        skb_queue_purge(&sk->sk_error_queue);
        skb_queue_purge(&sk->sk_write_queue);
        sock_put(sk);
}
static void my_proto_close(struct sock *sk, long timeout)
{    
        lock_sock(sk);
        
        sock_hold(sk);        /* increment sk_refcnt */
        
        sock_orphan(sk);    /* set sk_flag SOCK_DEAD flag */
        
        release_sock(sk);

        local_bh_disable();    /* close current cpu softirq */
        bh_lock_sock(sk);    /* spin_lock */

        stream_csk_destroy_sock(sk);

        bh_unlock_sock(sk);
        local_bh_enable();    /* spin_unlock */

        sock_put(sk);        /* if sk_refcnt = 0, call sk_free(sk) */
    
    printk(KERN_ALERT "my_proto_close ok\n");
}

struct my_priv_struct
{
    struct sock sk;
    int flag;
};

static struct proto my_proto =
{
    .name         = "my_proto",
    .owner        = THIS_MODULE,
    .close        = my_proto_close,
    .obj_size    = sizeof(struct my_priv_struct),
};

static int my_release(struct socket *sock)
{
    struct sock *sk = sock->sk;

    sock->sk = NULL;
    sk->sk_prot->close(sk, 0);

    printk(KERN_ALERT "my_release ok\n");

    return 0;
}

static struct proto_ops my_ops =
{    
    .family        = PF_MYFAMILY,
    .owner        = THIS_MODULE,
    .release    = my_release,    
};

static int family_create(struct socket *sock, int protocol)
{    
    struct sock *sk;

    sock->state     = SS_UNCONNECTED;
    sock->ops    = &my_ops;
    
    sk = sk_alloc(PF_MYFAMILY, GFP_KERNEL, &my_proto, 1);
     if (!sk)
    {
        printk(KERN_NOTICE "sk_alloc failure\n");    
        goto alloc_err;
    }
    
    sock_init_data(sock, sk);

    return 0;
alloc_err:
    return -1;
}

static struct net_proto_family family =
{
    .family    = PF_MYFAMILY,
    .create    = family_create,
    .owner    = THIS_MODULE,
};

static int __init private_init(void)
{
    int ret;

    ret = proto_register(&my_proto, 1);
    if (ret < 0)
    {
        printk(KERN_ALERT "proto_register failure\n");
        goto proto_err;
    }

    ret = sock_register(&family);
    if (ret < 0)
    {            
        printk(KERN_NOTICE "sock_register failure\n");    
        goto sock_err;
    }
    
    printk(KERN_NOTICE "sock_register success\n");

    return 0;
sock_err:
    proto_unregister(&my_proto);
proto_err:
    return -1;
}

static void __exit private_exit(void)
{
    sock_unregister(PF_MYFAMILY);
}

module_init(private_init);
module_exit(private_exit);
MODULE_LICENSE("GPL");