1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
4 * James Leu (jleu@mindspring.net).
5 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 * Copyright (C) 2001 by various other people who didn't put their name here.
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 static 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 = ðertap_user_info,
89 .kern = ðertap_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(ðertap_transport);
97 return 0;
98 }
99
100 late_initcall(register_ethertap);
101
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