1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/if_arp.h>
7#include <linux/init.h>
8#include <linux/netdevice.h>
9#include <net_kern.h>
10#include "slip.h"
11
12struct slip_init {
13	char *gate_addr;
14};
15
16static void slip_init(struct net_device *dev, void *data)
17{
18	struct uml_net_private *private;
19	struct slip_data *spri;
20	struct slip_init *init = data;
21
22	private = netdev_priv(dev);
23	spri = (struct slip_data *) private->user;
24
25	memset(spri->name, 0, sizeof(spri->name));
26	spri->addr = NULL;
27	spri->gate_addr = init->gate_addr;
28	spri->slave = -1;
29	spri->dev = dev;
30
31	slip_proto_init(&spri->slip);
32
33	dev->hard_header_len = 0;
34	dev->header_ops = NULL;
35	dev->addr_len = 0;
36	dev->type = ARPHRD_SLIP;
37	dev->tx_queue_len = 256;
38	dev->flags = IFF_NOARP;
39	printk("SLIP backend - SLIP IP = %s\n", spri->gate_addr);
40}
41
42static unsigned short slip_protocol(struct sk_buff *skbuff)
43{
44	return htons(ETH_P_IP);
45}
46
47static int slip_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
48{
49	return slip_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
50			      (struct slip_data *) &lp->user);
51}
52
53static int slip_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
54{
55	return slip_user_write(fd, skb->data, skb->len,
56			       (struct slip_data *) &lp->user);
57}
58
59static const struct net_kern_info slip_kern_info = {
60	.init			= slip_init,
61	.protocol		= slip_protocol,
62	.read			= slip_read,
63	.write			= slip_write,
64};
65
66static int slip_setup(char *str, char **mac_out, void *data)
67{
68	struct slip_init *init = data;
69
70	*init = ((struct slip_init) { .gate_addr = NULL });
71
72	if (str[0] != '\0')
73		init->gate_addr = str;
74	return 1;
75}
76
77static struct transport slip_transport = {
78	.list 		= LIST_HEAD_INIT(slip_transport.list),
79	.name 		= "slip",
80	.setup  	= slip_setup,
81	.user 		= &slip_user_info,
82	.kern 		= &slip_kern_info,
83	.private_size 	= sizeof(struct slip_data),
84	.setup_size 	= sizeof(struct slip_init),
85};
86
87static int register_slip(void)
88{
89	register_transport(&slip_transport);
90	return 0;
91}
92
93late_initcall(register_slip);
94