/*
 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and 
 * James Leu (jleu@mindspring.net).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 * Licensed under the GPL.
 */

#include "linux/init.h"
#include "linux/netdevice.h"
#include "linux/etherdevice.h"
#include "linux/init.h"
#include "net_kern.h"
#include "net_user.h"
#include "etap.h"

struct ethertap_init {
	char *dev_name;
	char *gate_addr;
};

static void etap_init(struct net_device *dev, void *data)
{
	struct uml_net_private *pri;
	struct ethertap_data *epri;
	struct ethertap_init *init = data;

	init_etherdev(dev, 0);
	pri = dev->priv;
	epri = (struct ethertap_data *) pri->user;
	*epri = ((struct ethertap_data)
		{ dev_name :		init->dev_name,
		  gate_addr :		init->gate_addr,
		  data_fd :		-1,
		  control_fd :		-1,
		  dev :			dev });

	printk("ethertap backend - %s", epri->dev_name);
	if(epri->gate_addr != NULL) 
		printk(", IP = %s", epri->gate_addr);
	printk("\n");
}

static int etap_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
{
	int len;

	*skb = ether_adjust_skb(*skb, ETH_HEADER_ETHERTAP);
	if(*skb == NULL) return(-ENOMEM);
	len = net_recvfrom(fd, (*skb)->mac.raw, 
			   (*skb)->dev->mtu + 2 * ETH_HEADER_ETHERTAP);
	if(len <= 0) return(len);
	skb_pull(*skb, 2);
	len -= 2;
	return(len);
}

static int etap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
{
	if(skb_headroom(*skb) < 2){
	  	struct sk_buff *skb2;

		skb2 = skb_realloc_headroom(*skb, 2);
		dev_kfree_skb(*skb);
		if (skb2 == NULL) return(-ENOMEM);
		*skb = skb2;
	}
	skb_push(*skb, 2);
	return(net_send(fd, (*skb)->data, (*skb)->len));
}

struct net_kern_info ethertap_kern_info = {
	init:			etap_init,
	protocol:		eth_protocol,
	read:			etap_read,
	write: 			etap_write,
};

int ethertap_setup(char *str, char **mac_out, void *data)
{
	struct ethertap_init *init = data;

	*init = ((struct ethertap_init)
		{ dev_name :	NULL,
		  gate_addr :	NULL });
	if(tap_setup_common(str, "ethertap", &init->dev_name, mac_out,
			    &init->gate_addr))
		return(0);
	if(init->dev_name == NULL){
		printk("ethertap_setup : Missing tap device name\n");
		return(0);
	}

	return(1);
}

static struct transport ethertap_transport = {
	list :		LIST_HEAD_INIT(ethertap_transport.list),
	name :		"ethertap",
	setup : 	ethertap_setup,
	user :		&ethertap_user_info,
	kern :		&ethertap_kern_info,
	private_size :	sizeof(struct ethertap_data),
};

static int register_ethertap(void)
{
	register_transport(&ethertap_transport);
	return(1);
}

__initcall(register_ethertap);

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-file-style: "linux"
 * End:
 */
