Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6] / arch / um / os-Linux / drivers / ethertap_kern.c
1 /*
2  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
3  * James Leu (jleu@mindspring.net).
4  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
5  * Copyright (C) 2001 by various other people who didn't put their name here.
6  * Licensed under the GPL.
7  */
8
9 #include <linux/init.h>
10 #include <linux/netdevice.h>
11 #include "etap.h"
12 #include "net_kern.h"
13
14 struct ethertap_init {
15         char *dev_name;
16         char *gate_addr;
17 };
18
19 static void etap_init(struct net_device *dev, void *data)
20 {
21         struct uml_net_private *pri;
22         struct ethertap_data *epri;
23         struct ethertap_init *init = data;
24
25         pri = netdev_priv(dev);
26         epri = (struct ethertap_data *) pri->user;
27         epri->dev_name = init->dev_name;
28         epri->gate_addr = init->gate_addr;
29         epri->data_fd = -1;
30         epri->control_fd = -1;
31         epri->dev = dev;
32
33         printk(KERN_INFO "ethertap backend - %s", epri->dev_name);
34         if (epri->gate_addr != NULL)
35                 printk(KERN_CONT ", IP = %s", epri->gate_addr);
36         printk(KERN_CONT "\n");
37 }
38
39 static int etap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
40 {
41         int len;
42
43         len = net_recvfrom(fd, skb_mac_header(skb),
44                            skb->dev->mtu + 2 + ETH_HEADER_ETHERTAP);
45         if (len <= 0)
46                 return(len);
47
48         skb_pull(skb, 2);
49         len -= 2;
50         return len;
51 }
52
53 static int etap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
54 {
55         skb_push(skb, 2);
56         return net_send(fd, skb->data, skb->len);
57 }
58
59 const struct net_kern_info ethertap_kern_info = {
60         .init                   = etap_init,
61         .protocol               = eth_protocol,
62         .read                   = etap_read,
63         .write                  = etap_write,
64 };
65
66 int ethertap_setup(char *str, char **mac_out, void *data)
67 {
68         struct ethertap_init *init = data;
69
70         *init = ((struct ethertap_init)
71                 { .dev_name     = NULL,
72                   .gate_addr    = NULL });
73         if (tap_setup_common(str, "ethertap", &init->dev_name, mac_out,
74                             &init->gate_addr))
75                 return 0;
76         if (init->dev_name == NULL) {
77                 printk(KERN_ERR "ethertap_setup : Missing tap device name\n");
78                 return 0;
79         }
80
81         return 1;
82 }
83
84 static struct transport ethertap_transport = {
85         .list           = LIST_HEAD_INIT(ethertap_transport.list),
86         .name           = "ethertap",
87         .setup          = ethertap_setup,
88         .user           = &ethertap_user_info,
89         .kern           = &ethertap_kern_info,
90         .private_size   = sizeof(struct ethertap_data),
91         .setup_size     = sizeof(struct ethertap_init),
92 };
93
94 static int register_ethertap(void)
95 {
96         register_transport(&ethertap_transport);
97         return 0;
98 }
99
100 late_initcall(register_ethertap);