nr_dev.c revision 3f2aadd041a7a3e732d182c3770b3fa95a2300b2 
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 */
9#include <linux/config.h>
10#include <linux/module.h>
11#include <linux/proc_fs.h>
12#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <linux/interrupt.h>
15#include <linux/fs.h>
16#include <linux/types.h>
17#include <linux/sysctl.h>
18#include <linux/string.h>
19#include <linux/socket.h>
20#include <linux/errno.h>
21#include <linux/fcntl.h>
22#include <linux/in.h>
23#include <linux/if_ether.h>	/* For the statistics structure. */
24
25#include <asm/system.h>
26#include <asm/uaccess.h>
27#include <asm/io.h>
28
29#include <linux/inet.h>
30#include <linux/netdevice.h>
31#include <linux/etherdevice.h>
32#include <linux/if_arp.h>
33#include <linux/skbuff.h>
34
35#include <net/ip.h>
36#include <net/arp.h>
37
38#include <net/ax25.h>
39#include <net/netrom.h>
40
41/*
42 *	Only allow IP over NET/ROM frames through if the netrom device is up.
43 */
44
45int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
46{
47	struct net_device_stats *stats = netdev_priv(dev);
48
49	if (!netif_running(dev)) {
50		stats->rx_errors++;
51		return 0;
52	}
53
54	stats->rx_packets++;
55	stats->rx_bytes += skb->len;
56
57	skb->protocol = htons(ETH_P_IP);
58
59	/* Spoof incoming device */
60	skb->dev      = dev;
61	skb->h.raw    = skb->data;
62	skb->nh.raw   = skb->data;
63	skb->pkt_type = PACKET_HOST;
64
65	netif_rx(skb);
66
67	return 1;
68}
69
70#ifdef CONFIG_INET
71
72static int nr_rebuild_header(struct sk_buff *skb)
73{
74	unsigned char *bp = skb->data;
75
76	if (arp_find(bp + 7, skb))
77		return 1;
78
79	bp[6] &= ~AX25_CBIT;
80	bp[6] &= ~AX25_EBIT;
81	bp[6] |= AX25_SSSID_SPARE;
82	bp    += AX25_ADDR_LEN;
83
84	bp[6] &= ~AX25_CBIT;
85	bp[6] |= AX25_EBIT;
86	bp[6] |= AX25_SSSID_SPARE;
87
88	return 0;
89}
90
91#else
92
93static int nr_rebuild_header(struct sk_buff *skb)
94{
95	return 1;
96}
97
98#endif
99
100static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
101	void *daddr, void *saddr, unsigned len)
102{
103	unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
104
105	memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
106	buff[6] &= ~AX25_CBIT;
107	buff[6] &= ~AX25_EBIT;
108	buff[6] |= AX25_SSSID_SPARE;
109	buff    += AX25_ADDR_LEN;
110
111	if (daddr != NULL)
112		memcpy(buff, daddr, dev->addr_len);
113	buff[6] &= ~AX25_CBIT;
114	buff[6] |= AX25_EBIT;
115	buff[6] |= AX25_SSSID_SPARE;
116	buff    += AX25_ADDR_LEN;
117
118	*buff++ = sysctl_netrom_network_ttl_initialiser;
119
120	*buff++ = NR_PROTO_IP;
121	*buff++ = NR_PROTO_IP;
122	*buff++ = 0;
123	*buff++ = 0;
124	*buff++ = NR_PROTOEXT;
125
126	if (daddr != NULL)
127		return 37;
128
129	return -37;
130}
131
132static int nr_set_mac_address(struct net_device *dev, void *addr)
133{
134	struct sockaddr *sa = addr;
135
136	if (dev->flags & IFF_UP)
137		ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
138
139	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
140
141	if (dev->flags & IFF_UP)
142		ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
143
144	return 0;
145}
146
147static int nr_open(struct net_device *dev)
148{
149	netif_start_queue(dev);
150	ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
151	return 0;
152}
153
154static int nr_close(struct net_device *dev)
155{
156	ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
157	netif_stop_queue(dev);
158	return 0;
159}
160
161static int nr_xmit(struct sk_buff *skb, struct net_device *dev)
162{
163	struct net_device_stats *stats = netdev_priv(dev);
164	unsigned int len;
165
166	len = skb->len;
167
168	if (!nr_route_frame(skb, NULL)) {
169		kfree_skb(skb);
170		stats->tx_errors++;
171		return 0;
172	}
173
174	stats->tx_packets++;
175	stats->tx_bytes += len;
176
177	return 0;
178}
179
180static struct net_device_stats *nr_get_stats(struct net_device *dev)
181{
182	return netdev_priv(dev);
183}
184
185void nr_setup(struct net_device *dev)
186{
187	SET_MODULE_OWNER(dev);
188	dev->mtu		= NR_MAX_PACKET_SIZE;
189	dev->hard_start_xmit	= nr_xmit;
190	dev->open		= nr_open;
191	dev->stop		= nr_close;
192
193	dev->hard_header	= nr_header;
194	dev->hard_header_len	= NR_NETWORK_LEN + NR_TRANSPORT_LEN;
195	dev->addr_len		= AX25_ADDR_LEN;
196	dev->type		= ARPHRD_NETROM;
197	dev->tx_queue_len	= 40;
198	dev->rebuild_header	= nr_rebuild_header;
199	dev->set_mac_address    = nr_set_mac_address;
200
201	/* New-style flags. */
202	dev->flags		= 0;
203
204	dev->get_stats 		= nr_get_stats;
205}
206