Change destination MAC

Hello.

I'm developing a kernel module in order to change the MAC address to the 
one I desired. For that I'm using the netfilter/ebtables hook. However I'm 
facing a problem, I don't know the reason why it happens.
The module works fine and seems to do its job. However that depends on the 
dest MAC address I put to the packet.
Let's explain it. If the dest MAC addr is under the control of the brigde 
(brctl showmacs br0) there is no problem when changing it, I can put 
whatever within this list.
However if I put another different from the ones in the list, the packet is 
not sent. I'm sniffing the channel and no packet get out of the device.

When exiting the NF_BR_POST_ROUTING it seems that the mac has been changed, 
but the packet never gets out.

Any reason for that.
Any help is more than welcome.

TA.

Here I post the code:

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_bridge.h>
#include <linux/socket.h>

struct nf_hook_ops hook_ex;

unsigned int function_hook( unsigned int hook, struct sk_buff **pskb, const 
struct net_device *in,
			    const struct net_device *out, int (*okfn)(struct sk_buff *))
{
	static int j = 0;
	
   unsigned char *data;
   int i;
	
	char a[] = {0x00, 0x02, 0x2d, 0x21, 0xb4, 0x65};
	
		struct sk_buff *nskb;
	
		nskb = skb_copy(*pskb, GFP_ATOMIC);
		if (!nskb)
			return NF_DROP;
		if ((*pskb)->sk)
			skb_set_owner_w(nskb, (*pskb)->sk);
		kfree_skb(*pskb);
		*pskb = nskb;

	memcpy(eth_hdr(*pskb)->h_dest, a, ETH_ALEN);
	
	data = (*pskb)->mac.raw;
	
	for (i=0;i<6;i++) {
		printk("%02X ", data[i]);
	}
	printk("   %d\n", j);
	printk("%s\n", out->name);
	
	(*pskb)->nfcache |= NFC_UNKNOWN;
	(*pskb)->nfcache |= NFC_ALTERED;
	

	return NF_ACCEPT;
}

static int __init init(void)
{
   // hook
   hook_ex.list.next = NULL;
   hook_ex.list.prev = NULL;
   hook_ex.hook = function_hook;
   //  hook_ex.list.flush = NULL;
   hook_ex.pf = PF_BRIDGE;
   hook_ex.hooknum = NF_BR_POST_ROUTING;
   return nf_register_hook(&hook_ex);
}

static void __exit fini(void)
{
   nf_unregister_hook(&hook_ex);
}

module_init(init);
module_exit(fini);





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