1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/netdevice.h>
7#include <linux/init.h>
8#include <linux/skbuff.h>
9#include <asm/errno.h>
10#include <net_kern.h>
11#include "tuntap.h"
12
13struct tuntap_init {
14	char *dev_name;
15	char *gate_addr;
16};
17
18static void tuntap_init(struct net_device *dev, void *data)
19{
20	struct uml_net_private *pri;
21	struct tuntap_data *tpri;
22	struct tuntap_init *init = data;
23
24	pri = netdev_priv(dev);
25	tpri = (struct tuntap_data *) pri->user;
26	tpri->dev_name = init->dev_name;
27	tpri->fixed_config = (init->dev_name != NULL);
28	tpri->gate_addr = init->gate_addr;
29	tpri->fd = -1;
30	tpri->dev = dev;
31
32	printk(KERN_INFO "TUN/TAP backend - ");
33	if (tpri->gate_addr != NULL)
34		printk(KERN_CONT "IP = %s", tpri->gate_addr);
35	printk(KERN_CONT "\n");
36}
37
38static int tuntap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
39{
40	return net_read(fd, skb_mac_header(skb),
41			skb->dev->mtu + ETH_HEADER_OTHER);
42}
43
44static int tuntap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
45{
46	return net_write(fd, skb->data, skb->len);
47}
48
49const struct net_kern_info tuntap_kern_info = {
50	.init			= tuntap_init,
51	.protocol		= eth_protocol,
52	.read			= tuntap_read,
53	.write 			= tuntap_write,
54};
55
56int tuntap_setup(char *str, char **mac_out, void *data)
57{
58	struct tuntap_init *init = data;
59
60	*init = ((struct tuntap_init)
61		{ .dev_name 	= NULL,
62		  .gate_addr 	= NULL });
63	if (tap_setup_common(str, "tuntap", &init->dev_name, mac_out,
64			    &init->gate_addr))
65		return 0;
66
67	return 1;
68}
69
70static struct transport tuntap_transport = {
71	.list 		= LIST_HEAD_INIT(tuntap_transport.list),
72	.name 		= "tuntap",
73	.setup  	= tuntap_setup,
74	.user 		= &tuntap_user_info,
75	.kern 		= &tuntap_kern_info,
76	.private_size 	= sizeof(struct tuntap_data),
77	.setup_size 	= sizeof(struct tuntap_init),
78};
79
80static int register_tuntap(void)
81{
82	register_transport(&tuntap_transport);
83	return 0;
84}
85
86late_initcall(register_tuntap);
87