#include <linux/config.h>
#include <linux/module.h>

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/locks.h>
#include <linux/unistd.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/lockd/bind.h>

#include <linux/socket.h>
#include <linux/in.h>
#include <linux/net.h>
#include <linux/udp.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/udp.h>

#include <asm/system.h>
#include <asm/uaccess.h>


static void mod_data_ready(struct sock *sk, int len)
{
    printk("data_ready callback\n");
}

static void mod_state_change(struct sock *sk)
{
    printk("state_change callback\n");
}

static void mod_write_space(struct sock *sk)
{
    printk("write_space callback\n");
}


static struct socket   *sock;

static inline int 
mod_rcv_msg()
{
        unsigned char buf[4];
	
	struct msghdr      msg;
        mm_segment_t     oldfs;
        int             result;
        struct iovec       iov;

        iov.iov_base = &buf[0];
        iov.iov_len = 1;

        msg.msg_flags   = MSG_DONTWAIT;
        msg.msg_iov     = &iov;
        msg.msg_iovlen  = 1;
        msg.msg_name    = NULL;
        msg.msg_namelen = 0;
        msg.msg_control = NULL;
        msg.msg_controllen = 0;

        oldfs = get_fs(); set_fs(get_ds());
        result = sock_recvmsg(sock, &msg, 1, MSG_DONTWAIT);
        set_fs(oldfs);

        printk("Receiving message %c %d bytes long\n", buf[0], result);
        return result;
}


int
init_module(void)
{
      struct sockaddr_in sap;
      int err;
      int i;

      sap.sin_family = AF_INET;
      sap.sin_port = 13570;
      sap.sin_addr.s_addr = 16777343;

      if ((err = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
          printk("can't create socket (%d).\n", -err);
	  return -1;
      }

      sock->sk->data_ready   = mod_data_ready;
      sock->sk->state_change = mod_state_change;
      sock->sk->write_space  = mod_write_space;
      
      err = sock->ops->connect(sock, (struct sockaddr *) &sap, 
                               sizeof(struct sockaddr_in), 0);

      if (err < 0) {
          sock_release(sock);
          printk("TCP connect failed (%d).\n", -err);
	  return -1;
      }


      for (i=0;i<10;i++)
           mod_rcv_msg();

      return 0;
}

void
cleanup_module(void)
{
      sock_release(sock);
}