内核socket编程

 

现在需要在netfilter中实现UDP消息包的交互，使用Socket编程机制。

#include
#include
#include
#include
#include
#include
#include
#include


static struct socket *sock;
static struct work_struct work;

static int my_sendto(struct socket *sock, void * buff, size_t len,
unsigned flags, struct sockaddr *addr, int addr_len)
{
struct kvec vec;
struct msghdr msg;

vec.iov_base=buff;
vec.iov_len=len;

memset(&msg, 0x00, sizeof(msg));
msg.msg_name=addr;
msg.msg_namelen=addr_len;
msg.msg_flags = flags | MSG_DONTWAIT;

return kernel_sendmsg(sock, &msg, &vec, 1, len);
}

static char buffer[128];
static void sendmsg(void *dummy)
{
int n;
struct sockaddr_in addr;
memset(&addr, 0x00, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(1000);
addr.sin_addr.s_addr = in_aton("61.139.2.69");
n = my_sendto(sock, buffer, 128, 0, (struct sockaddr *)&addr, sizeof(addr));
printk("send %i bytes\n", n);
}

static int socket_init(void)
{
INIT_WORK(&work, sendmsg, NULL);
sock_create_kern(PF_INET, SOCK_DGRAM, 0, &sock);
//不知加了GFP_ATOMIC，之后还会不会阻塞!!
//sock->sk->sk_allocation = GFP_ATOMIC;
schedule_delayed_work(&work, 2 * HZ);//两秒后sendmsg在kevent kernel thread中被调用
return 0;
}

static void socket_exit(void)
{
sock_release(sock);
}

module_init(socket_init);
module_exit(socket_exit);

我的是2.6.12的内核！
代码没有安全检查，在没有看到"send nnn bytes"之前不要rmmod.