aboutsummaryrefslogtreecommitdiffstats
path: root/net/netrom/nr_dev.c
blob: 6ae063cebf7de71082f0b526ecbfcd935f70dff4 (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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/sysctl.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/in.h>
#include <linux/if_ether.h>	/* For the statistics structure. */
#include <linux/slab.h>
#include <linux/uaccess.h>

#include <asm/io.h>

#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>

#include <net/ip.h>
#include <net/arp.h>

#include <net/ax25.h>
#include <net/netrom.h>

/*
 *	Only allow IP over NET/ROM frames through if the netrom device is up.
 */

int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
{
	struct net_device_stats *stats = &dev->stats;

	if (!netif_running(dev)) {
		stats->rx_dropped++;
		return 0;
	}

	stats->rx_packets++;
	stats->rx_bytes += skb->len;

	skb->protocol = htons(ETH_P_IP);

	/* Spoof incoming device */
	skb->dev      = dev;
	skb->mac_header = skb->network_header;
	skb_reset_network_header(skb);
	skb->pkt_type = PACKET_HOST;

	netif_rx(skb);

	return 1;
}

#ifdef CONFIG_INET

static int nr_rebuild_header(struct sk_buff *skb)
{
	unsigned char *bp = skb->data;

	if (arp_find(bp + 7, skb))
		return 1;

	bp[6] &= ~AX25_CBIT;
	bp[6] &= ~AX25_EBIT;
	bp[6] |= AX25_SSSID_SPARE;
	bp    += AX25_ADDR_LEN;

	bp[6] &= ~AX25_CBIT;
	bp[6] |= AX25_EBIT;
	bp[6] |= AX25_SSSID_SPARE;

	return 0;
}

#else

static int nr_rebuild_header(struct sk_buff *skb)
{
	return 1;
}

#endif

static int nr_header(struct sk_buff *skb, struct net_device *dev,
		     unsigned short type,
		     const void *daddr, const void *saddr, unsigned int len)
{
	unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);

	memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
	buff[6] &= ~AX25_CBIT;
	buff[6] &= ~AX25_EBIT;
	buff[6] |= AX25_SSSID_SPARE;
	buff    += AX25_ADDR_LEN;

	if (daddr != NULL)
		memcpy(buff, daddr, dev->addr_len);
	buff[6] &= ~AX25_CBIT;
	buff[6] |= AX25_EBIT;
	buff[6] |= AX25_SSSID_SPARE;
	buff    += AX25_ADDR_LEN;

	*buff++ = sysctl_netrom_network_ttl_initialiser;

	*buff++ = NR_PROTO_IP;
	*buff++ = NR_PROTO_IP;
	*buff++ = 0;
	*buff++ = 0;
	*buff++ = NR_PROTOEXT;

	if (daddr != NULL)
		return 37;

	return -37;
}

static int __must_check nr_set_mac_address(struct net_device *dev, void *addr)
{
	struct sockaddr *sa = addr;
	int err;

	if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
		return 0;

	if (dev->flags & IFF_UP) {
		err = ax25_listen_register((ax25_address *)sa->sa_data, NULL);
		if (err)
			return err;

		ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
	}

	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);

	return 0;
}

static int nr_open(struct net_device *dev)
{
	int err;

	err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
	if (err)
		return err;

	netif_start_queue(dev);

	return 0;
}

static int nr_close(struct net_device *dev)
{
	ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
	netif_stop_queue(dev);
	return 0;
}

static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct net_device_stats *stats = &dev->stats;
	unsigned int len = skb->len;

	if (!nr_route_frame(skb, NULL)) {
		kfree_skb(skb);
		stats->tx_errors++;
		return NETDEV_TX_OK;
	}

	stats->tx_packets++;
	stats->tx_bytes += len;

	return NETDEV_TX_OK;
}

static const struct header_ops nr_header_ops = {
	.create	= nr_header,
	.rebuild= nr_rebuild_header,
};

static const struct net_device_ops nr_netdev_ops = {
	.ndo_open		= nr_open,
	.ndo_stop		= nr_close,
	.ndo_start_xmit		= nr_xmit,
	.ndo_set_mac_address    = nr_set_mac_address,
};

void nr_setup(struct net_device *dev)
{
	dev->mtu		= NR_MAX_PACKET_SIZE;
	dev->netdev_ops		= &nr_netdev_ops;
	dev->header_ops		= &nr_header_ops;
	dev->hard_header_len	= NR_NETWORK_LEN + NR_TRANSPORT_LEN;
	dev->addr_len		= AX25_ADDR_LEN;
	dev->type		= ARPHRD_NETROM;

	/* New-style flags. */
	dev->flags		= IFF_NOARP;
}

Privacy Policy