Send.c

[root@server1 ~]# cat send.c
/*                                                                                                            
* $Id: hello.c,v 1.5 2004/10/26 03:32:21 corbet Exp $    
*/                                                                                                        
#include <linux/init.h>
#include <linux/module.h>
#include <lp.h>
MODULE_LICENSE("Dual BSD/GPL");

int send = 0;
module_param(send, int, S_IRUGO);

net_device_t * NIC = NULL;

int lp_recv(sk_buff_t * skb, net_device_t * dev, packet_type_t * pt, net_device_t * d){
                PDEBUG("lp_recv is being invoked\n");
                return NET_RX_SUCCESS;
}

packet_type_t lp_ptype = {
                .type = __constant_htons(ETH_P_LP),
                .func = lp_recv,
                .dev = NULL,
                .af_packet_priv = NULL,
};

int lp_send_skb(sk_buff_t * skb)
{
                ethhdr_t * eth = NULL;
                char * dest = kmalloc(ETH_ALEN, GFP_KERNEL);
                if(!dest)
                {
                                PDEBUG("alloc dest fail");
                }
                dest[0] = 0x00;
                dest[1] = 0x16;
                dest[2] = 0x3e;
                dest[3] = 0x53;
                dest[4] = 0x12;
                dest[5] = 0x51;

                skb->data_len = 0;
                skb->len =    LINK_HDR + 10;
                skb->tail = skb->data + LINK_HDR + 10;
                skb->mac.raw = skb->nh.raw = skb->h.raw = skb->data;
                skb->dev = NIC;
                skb->protocol = htons(ETH_P_LP);
                eth = (ethhdr_t *)skb->data;
                eth->h_proto = htons(ETH_P_LP);
                memcpy(eth->h_dest, dest, ETH_ALEN);
                memcpy(eth->h_source, NIC->dev_addr, ETH_ALEN);
                if(dev_queue_xmit(skb)){
                                return -1;
                }
                return 0;
}

static int send_init(void)
{
                sk_buff_t * skb;
                if(!(NIC = dev_get_by_name("eth0")))
                {
                                PDEBUG("NIC is null\n");
                                return -ENODEV;
                }
                dev_add_pack(&lp_ptype);
                PDEBUG("lp init\n");
                if(send)
                {
                                if(!(skb = alloc_skb(LINK_HDR+10, GFP_KERNEL)))
                                {
                                                PDEBUG("alloc skb fail\n");
                                }
                                if(!lp_send_skb(skb))
                                {
                                                PDEBUG("send success\n");
                                }
                                kfree_skb(skb);
                }
                return 0;
}

static void send_exit(void)
{
                dev_remove_pack(&lp_ptype);
                dev_put(NIC);
                PDEBUG("lp exit\n");
}

module_init(send_init);
module_exit(send_exit);