xref: /openbmc/linux/arch/um/drivers/slirp_kern.c (revision 9470114d)
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 
14 struct slirp_init {
15 	struct arg_list_dummy_wrapper argw;  /* XXX should be simpler... */
16 };
17 
18 static 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 
47 static unsigned short slirp_protocol(struct sk_buff *skbuff)
48 {
49 	return htons(ETH_P_IP);
50 }
51 
52 static 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 
58 static 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 
64 const 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 
71 static 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 
104 static 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 
114 static int register_slirp(void)
115 {
116 	register_transport(&slirp_transport);
117 	return 0;
118 }
119 
120 late_initcall(register_slirp);
121