summaryrefslogtreecommitdiffstats
path: root/drivers/net/wan/hdlc_raw_eth.c
blob: 8bd3ed9058132627f053280194070a1367002483 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * Generic HDLC support routines for Linux
 * HDLC Ethernet emulation support
 *
 * Copyright (C) 2002-2006 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/hdlc.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pkt_sched.h>
#include <linux/poll.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>

static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr);

static netdev_tx_t eth_tx(struct sk_buff *skb, struct net_device *dev)
{
	int pad = ETH_ZLEN - skb->len;
	if (pad > 0) {		/* Pad the frame with zeros */
		int len = skb->len;
		if (skb_tailroom(skb) < pad)
			if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) {
				dev->stats.tx_dropped++;
				dev_kfree_skb(skb);
				return 0;
			}
		skb_put(skb, pad);
		memset(skb->data + len, 0, pad);
	}
	return dev_to_hdlc(dev)->xmit(skb, dev);
}


static struct hdlc_proto proto = {
	.type_trans	= eth_type_trans,
	.xmit		= eth_tx,
	.ioctl		= raw_eth_ioctl,
	.module		= THIS_MODULE,
};


static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
{
	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
	const size_t size = sizeof(raw_hdlc_proto);
	raw_hdlc_proto new_settings;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	unsigned int old_qlen;
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		if (dev_to_hdlc(dev)->proto != &proto)
			return -EINVAL;
		ifr->ifr_settings.type = IF_PROTO_HDLC_ETH;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}
		if (copy_to_user(raw_s, hdlc->state, size))
			return -EFAULT;
		return 0;

	case IF_PROTO_HDLC_ETH:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		if (dev->flags & IFF_UP)
			return -EBUSY;

		if (copy_from_user(&new_settings, raw_s, size))
			return -EFAULT;

		if (new_settings.encoding == ENCODING_DEFAULT)
			new_settings.encoding = ENCODING_NRZ;

		if (new_settings.parity == PARITY_DEFAULT)
			new_settings.parity = PARITY_CRC16_PR1_CCITT;

		result = hdlc->attach(dev, new_settings.encoding,
				      new_settings.parity);
		if (result)
			return result;

		result = attach_hdlc_protocol(dev, &proto,
					      sizeof(raw_hdlc_proto));
		if (result)
			return result;
		memcpy(hdlc->state, &new_settings, size);
		old_qlen = dev->tx_queue_len;
		ether_setup(dev);
		dev->tx_queue_len = old_qlen;
		eth_hw_addr_random(dev);
		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
		netif_dormant_off(dev);
		return 0;
	}

	return -EINVAL;
}


static int __init mod_init(void)
{
	register_hdlc_protocol(&proto);
	return 0;
}



static void __exit mod_exit(void)
{
	unregister_hdlc_protocol(&proto);
}


module_init(mod_init);
module_exit(mod_exit);

MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC");
MODULE_LICENSE("GPL v2");