kernel udp 例子

#include <asm/atomic.h>
#include <asm/byteorder.h>
#include <asm/checksum.h>
#include <asm/unaligned.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/types.h>
#include <linux/kthread.h>
#include <linux/wait.h>
#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/sysctl.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/ip.h>
#include <linux/workqueue.h>
#include <linux/jiffies.h>
#include <linux/route.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/mutex.h>
#include <linux/compiler.h>
#include <linux/icmp.h>
#include <linux/jhash.h>
#include <linux/list.h>
#include <linux/inet.h>
#include <linux/spinlock_types.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/route.h>
#include <net/inet_connection_sock.h>
#include <net/request_sock.h>
#include <net/icmp.h>
#include <net/ip.h>

#define err(msg) printk(KERN_ERR "%s failed.\n", msg)
#define SA struct sockaddr

static void transfer_data(struct socket *sock)
{
    struct msghdr msg;
    struct kvec vec;
    char buff[576];    
    int len;
    struct sockaddr_in saddr;

    for (;;) {
        memset(&msg, '\0', sizeof(msg));
        vec.iov_base = (void *)buff;
        vec.iov_len = sizeof(buff);

        memset(&msg, '\0', sizeof(msg));
        msg.msg_name = &saddr;
        msg.msg_namelen = sizeof(saddr);

        len = kernel_recvmsg(sock, &msg, &vec, 1, sizeof(buff), 0);
        if (len <= 0)
            break;

        vec.iov_base = (void *)buff;
        vec.iov_len = len;
        kernel_sendmsg(sock, &msg, &vec, 1, len);
    }
}

static int __init main_init(void)
{
    struct socket *sock;
    int rc;
    struct sockaddr_in addr;

    rc = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
    if (rc < 0) {
        err("sock_create_kern");
        goto out;
    }
    
    memset(&addr, '\0', sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(7878);
    addr.sin_addr.s_addr = in_aton("192.168.10.188");

    if (kernel_bind(sock, (SA *)&addr, sizeof(addr)) != 0) {
        err("kernel_bind");
        goto err;
    }

    transfer_data(sock);

    sock_release(sock);
    return 0;
err:
    sock_release(sock);
out:
    return -1;
}

static void __exit main_exit(void)
{
}

module_init(main_init);
module_exit(main_exit);
MODULE_LICENSE("GPL");