xref: /openbmc/linux/arch/um/drivers/slip_kern.c (revision dbddf429)
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 
12 struct slip_init {
13 	char *gate_addr;
14 };
15 
slip_init(struct net_device * dev,void * data)16 static 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 
slip_protocol(struct sk_buff * skbuff)42 static unsigned short slip_protocol(struct sk_buff *skbuff)
43 {
44 	return htons(ETH_P_IP);
45 }
46 
slip_read(int fd,struct sk_buff * skb,struct uml_net_private * lp)47 static 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 
slip_write(int fd,struct sk_buff * skb,struct uml_net_private * lp)53 static 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 
59 static 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 
slip_setup(char * str,char ** mac_out,void * data)66 static 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 
77 static 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 
register_slip(void)87 static int register_slip(void)
88 {
89 	register_transport(&slip_transport);
90 	return 0;
91 }
92 
93 late_initcall(register_slip);
94