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(slip: &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, buf: skb_mac_header(skb), len: skb->dev->mtu,
55 pri: (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, buf: skb->data, len: skb->len,
61 pri: (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

source code of linux/arch/um/drivers/slirp_kern.c