nr_dev.c revision c1d2bbe1cd6c7bbdc6d532cefebb66c7efb789ce 
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/module.h>
10#include <linux/proc_fs.h>
11#include <linux/kernel.h>
12#include <linux/interrupt.h>
13#include <linux/fs.h>
14#include <linux/types.h>
15#include <linux/sysctl.h>
16#include <linux/string.h>
17#include <linux/socket.h>
18#include <linux/errno.h>
19#include <linux/fcntl.h>
20#include <linux/in.h>
21#include <linux/if_ether.h>	/* For the statistics structure. */
22
23#include <asm/system.h>
24#include <asm/uaccess.h>
25#include <asm/io.h>
26
27#include <linux/inet.h>
28#include <linux/netdevice.h>
29#include <linux/etherdevice.h>
30#include <linux/if_arp.h>
31#include <linux/skbuff.h>
32
33#include <net/ip.h>
34#include <net/arp.h>
35
36#include <net/ax25.h>
37#include <net/netrom.h>
38
39/*
40 *	Only allow IP over NET/ROM frames through if the netrom device is up.
41 */
42
43int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
44{
45	struct net_device_stats *stats = netdev_priv(dev);
46
47	if (!netif_running(dev)) {
48		stats->rx_dropped++;
49		return 0;
50	}
51
52	stats->rx_packets++;
53	stats->rx_bytes += skb->len;
54
55	skb->protocol = htons(ETH_P_IP);
56
57	/* Spoof incoming device */
58	skb->dev      = dev;
59	skb_reset_mac_header(skb);
60	skb_reset_network_header(skb);
61	skb->pkt_type = PACKET_HOST;
62
63	netif_rx(skb);
64
65	return 1;
66}
67
68#ifdef CONFIG_INET
69
70static int nr_rebuild_header(struct sk_buff *skb)
71{
72	unsigned char *bp = skb->data;
73
74	if (arp_find(bp + 7, skb))
75		return 1;
76
77	bp[6] &= ~AX25_CBIT;
78	bp[6] &= ~AX25_EBIT;
79	bp[6] |= AX25_SSSID_SPARE;
80	bp    += AX25_ADDR_LEN;
81
82	bp[6] &= ~AX25_CBIT;
83	bp[6] |= AX25_EBIT;
84	bp[6] |= AX25_SSSID_SPARE;
85
86	return 0;
87}
88
89#else
90
91static int nr_rebuild_header(struct sk_buff *skb)
92{
93	return 1;
94}
95
96#endif
97
98static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
99	void *daddr, void *saddr, unsigned len)
100{
101	unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
102
103	memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
104	buff[6] &= ~AX25_CBIT;
105	buff[6] &= ~AX25_EBIT;
106	buff[6] |= AX25_SSSID_SPARE;
107	buff    += AX25_ADDR_LEN;
108
109	if (daddr != NULL)
110		memcpy(buff, daddr, dev->addr_len);
111	buff[6] &= ~AX25_CBIT;
112	buff[6] |= AX25_EBIT;
113	buff[6] |= AX25_SSSID_SPARE;
114	buff    += AX25_ADDR_LEN;
115
116	*buff++ = sysctl_netrom_network_ttl_initialiser;
117
118	*buff++ = NR_PROTO_IP;
119	*buff++ = NR_PROTO_IP;
120	*buff++ = 0;
121	*buff++ = 0;
122	*buff++ = NR_PROTOEXT;
123
124	if (daddr != NULL)
125		return 37;
126
127	return -37;
128}
129
130static int __must_check nr_set_mac_address(struct net_device *dev, void *addr)
131{
132	struct sockaddr *sa = addr;
133	int err;
134
135	if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
136		return 0;
137
138	if (dev->flags & IFF_UP) {
139		err = ax25_listen_register((ax25_address *)sa->sa_data, NULL);
140		if (err)
141			return err;
142
143		ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
144	}
145
146	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
147
148	return 0;
149}
150
151static int nr_open(struct net_device *dev)
152{
153	int err;
154
155	err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
156	if (err)
157		return err;
158
159	netif_start_queue(dev);
160
161	return 0;
162}
163
164static int nr_close(struct net_device *dev)
165{
166	ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
167	netif_stop_queue(dev);
168	return 0;
169}
170
171static int nr_xmit(struct sk_buff *skb, struct net_device *dev)
172{
173	struct nr_private *nr = netdev_priv(dev);
174	struct net_device_stats *stats = &nr->stats;
175	unsigned int len = skb->len;
176
177	if (!nr_route_frame(skb, NULL)) {
178		kfree_skb(skb);
179		stats->tx_errors++;
180		return 0;
181	}
182
183	stats->tx_packets++;
184	stats->tx_bytes += len;
185
186	return 0;
187}
188
189static struct net_device_stats *nr_get_stats(struct net_device *dev)
190{
191	struct nr_private *nr = netdev_priv(dev);
192
193	return &nr->stats;
194}
195
196void nr_setup(struct net_device *dev)
197{
198	dev->mtu		= NR_MAX_PACKET_SIZE;
199	dev->hard_start_xmit	= nr_xmit;
200	dev->open		= nr_open;
201	dev->stop		= nr_close;
202
203	dev->hard_header	= nr_header;
204	dev->hard_header_len	= NR_NETWORK_LEN + NR_TRANSPORT_LEN;
205	dev->addr_len		= AX25_ADDR_LEN;
206	dev->type		= ARPHRD_NETROM;
207	dev->rebuild_header	= nr_rebuild_header;
208	dev->set_mac_address    = nr_set_mac_address;
209
210	/* New-style flags. */
211	dev->flags		= IFF_NOARP;
212
213	dev->get_stats 		= nr_get_stats;
214}
215