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 <linux/string.h>
10#include <net_kern.h>
11#include <net_user.h>
12#include "slirp.h"
13
14struct slirp_init {
15	struct arg_list_dummy_wrapper argw;  /* XXX should be simpler... */
16};
17
18static void slirp_init(struct net_device *dev, void *data)
19{
20	struct uml_net_private *private;
21	struct slirp_data *spri;
22	struct slirp_init *init = data;
23	int i;
24
25	private = netdev_priv(dev);
26	spri = (struct slirp_data *) private->user;
27
28	spri->argw = init->argw;
29	spri->pid = -1;
30	spri->slave = -1;
31	spri->dev = dev;
32
33	slip_proto_init(&spri->slip);
34
35	dev->hard_header_len = 0;
36	dev->header_ops = NULL;
37	dev->addr_len = 0;
38	dev->type = ARPHRD_SLIP;
39	dev->tx_queue_len = 256;
40	dev->flags = IFF_NOARP;
41	printk("SLIRP backend - command line:");
42	for (i = 0; spri->argw.argv[i] != NULL; i++)
43		printk(" '%s'",spri->argw.argv[i]);
44	printk("\n");
45}
46
47static unsigned short slirp_protocol(struct sk_buff *skbuff)
48{
49	return htons(ETH_P_IP);
50}
51
52static int slirp_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
53{
54	return slirp_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
55			       (struct slirp_data *) &lp->user);
56}
57
58static int slirp_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
59{
60	return slirp_user_write(fd, skb->data, skb->len,
61				(struct slirp_data *) &lp->user);
62}
63
64const struct net_kern_info slirp_kern_info = {
65	.init			= slirp_init,
66	.protocol		= slirp_protocol,
67	.read			= slirp_read,
68	.write			= slirp_write,
69};
70
71static int slirp_setup(char *str, char **mac_out, void *data)
72{
73	struct slirp_init *init = data;
74	int i=0;
75
76	*init = ((struct slirp_init) { .argw = { { "slirp", NULL  } } });
77
78	str = split_if_spec(str, mac_out, NULL);
79
80	if (str == NULL) /* no command line given after MAC addr */
81		return 1;
82
83	do {
84		if (i >= SLIRP_MAX_ARGS - 1) {
85			printk(KERN_WARNING "slirp_setup: truncating slirp "
86			       "arguments\n");
87			break;
88		}
89		init->argw.argv[i++] = str;
90		while(*str && *str!=',') {
91			if (*str == '_')
92				*str=' ';
93			str++;
94		}
95		if (*str != ',')
96			break;
97		*str++ = '\0';
98	} while (1);
99
100	init->argw.argv[i] = NULL;
101	return 1;
102}
103
104static struct transport slirp_transport = {
105	.list 		= LIST_HEAD_INIT(slirp_transport.list),
106	.name 		= "slirp",
107	.setup  	= slirp_setup,
108	.user 		= &slirp_user_info,
109	.kern 		= &slirp_kern_info,
110	.private_size 	= sizeof(struct slirp_data),
111	.setup_size 	= sizeof(struct slirp_init),
112};
113
114static int register_slirp(void)
115{
116	register_transport(&slirp_transport);
117	return 0;
118}
119
120late_initcall(register_slirp);
121