xref: /openbmc/linux/arch/um/os-Linux/drivers/tuntap_kern.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/stddef.h"
7 #include "linux/netdevice.h"
8 #include "linux/etherdevice.h"
9 #include "linux/skbuff.h"
10 #include "linux/init.h"
11 #include "asm/errno.h"
12 #include "net_kern.h"
13 #include "net_user.h"
14 #include "tuntap.h"
15 
16 struct tuntap_init {
17 	char *dev_name;
18 	char *gate_addr;
19 };
20 
21 static void tuntap_init(struct net_device *dev, void *data)
22 {
23 	struct uml_net_private *pri;
24 	struct tuntap_data *tpri;
25 	struct tuntap_init *init = data;
26 
27 	pri = dev->priv;
28 	tpri = (struct tuntap_data *) pri->user;
29 	tpri->dev_name = init->dev_name;
30 	tpri->fixed_config = (init->dev_name != NULL);
31 	tpri->gate_addr = init->gate_addr;
32 	tpri->fd = -1;
33 	tpri->dev = dev;
34 
35 	printk("TUN/TAP backend - ");
36 	if (tpri->gate_addr != NULL)
37 		printk("IP = %s", tpri->gate_addr);
38 	printk("\n");
39 }
40 
41 static int tuntap_read(int fd, struct sk_buff **skb,
42 		       struct uml_net_private *lp)
43 {
44 	*skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
45 	if(*skb == NULL) return(-ENOMEM);
46 	return(net_read(fd, (*skb)->mac.raw,
47 			(*skb)->dev->mtu + ETH_HEADER_OTHER));
48 }
49 
50 static int tuntap_write(int fd, struct sk_buff **skb,
51 			struct uml_net_private *lp)
52 {
53 	return(net_write(fd, (*skb)->data, (*skb)->len));
54 }
55 
56 struct net_kern_info tuntap_kern_info = {
57 	.init			= tuntap_init,
58 	.protocol		= eth_protocol,
59 	.read			= tuntap_read,
60 	.write 			= tuntap_write,
61 };
62 
63 int tuntap_setup(char *str, char **mac_out, void *data)
64 {
65 	struct tuntap_init *init = data;
66 
67 	*init = ((struct tuntap_init)
68 		{ .dev_name 	= NULL,
69 		  .gate_addr 	= NULL });
70 	if(tap_setup_common(str, "tuntap", &init->dev_name, mac_out,
71 			    &init->gate_addr))
72 		return(0);
73 
74 	return(1);
75 }
76 
77 static struct transport tuntap_transport = {
78 	.list 		= LIST_HEAD_INIT(tuntap_transport.list),
79 	.name 		= "tuntap",
80 	.setup  	= tuntap_setup,
81 	.user 		= &tuntap_user_info,
82 	.kern 		= &tuntap_kern_info,
83 	.private_size 	= sizeof(struct tuntap_data),
84 	.setup_size 	= sizeof(struct tuntap_init),
85 };
86 
87 static int register_tuntap(void)
88 {
89 	register_transport(&tuntap_transport);
90 	return(1);
91 }
92 
93 __initcall(register_tuntap);
94 
95 /*
96  * Overrides for Emacs so that we follow Linus's tabbing style.
97  * Emacs will notice this stuff at the end of the file and automatically
98  * adjust the settings for this buffer only.  This must remain at the end
99  * of the file.
100  * ---------------------------------------------------------------------------
101  * Local variables:
102  * c-file-style: "linux"
103  * End:
104  */
105