kernel socket 例子

#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/net.h>
#include <net/sock.h>

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

static struct socket * create_sock(const char *ip, int port)
{
        struct socket *sock;
        struct sockaddr_in addr;

        if (sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock) != 0) {
                err("sock_create_kern");
                goto out;
        }

        sock->sk->sk_reuse = 1;

        memset(&addr, '\0', sizeof(addr));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = in_aton(ip);

        if (kernel_bind(sock, (SA *)&addr, sizeof(addr)) != 0) {
                err("kernel_bind");
                goto err;
        }
        if (kernel_listen(sock, 10) != 0) {
                err("kernel_listen");
                goto err;
        }

        return sock;
err:
        sock_release(sock);
out:
        return NULL;
}

static void transfer_data(struct socket *newsock)
{
        struct msghdr msg;
        struct kvec vec;
        char buff[1024];
        int len;
        int num;

        for (;;) {
                memset(&msg, '\0', sizeof(msg));
                memset(buff, '\0', sizeof(buff));

                vec.iov_base = (void *)buff;
                vec.iov_len = 1024;

                len = kernel_recvmsg(newsock, &msg, &vec, 1, 1024, 0);
                if (len <= 0)
                        break;
                printk(KERN_INFO "len = %d\n", len);

                memset(&msg, '\0', sizeof(msg));
                vec.iov_base = (void *)buff;
                vec.iov_len = len;
                num = kernel_sendmsg(newsock, &msg, &vec, 1, len);
        }
}

static void do_loop(struct socket *sock)
{
        struct socket *newsock;


        for (;;) {
                if (kernel_accept(sock, &newsock, 0) != 0) {
                        err("kernel_accept");
                        break;
                }

                transfer_data(newsock);
                sock_release(newsock);
        }
}

static int __init hello_init(void)
{
        struct socket *sock;

        sock = create_sock("0.0.0.0", 7777);
        if (sock == NULL) {
                err("create_sock");
                goto out;
        }

        do_loop(sock);
        sock_release(sock);

        return 0;
out:
        return -1;
}

static void __exit hello_exit(void)
{
}

module_init(hello_init);
module_exit(hello_exit);
MODULE_LICENSE("GPL");